Abstract
Aim: We analyzed survival of patients diagnosed with ampullary cancer (AC) and pancreatic ductal adenocarcinomas (PDAC). Patients and Methods: Between 1996 and 2009, 505 and 69 patients diagnosed with PDAC and AC, respectively, were identified. Overall survival was analyzed according to tumor entity, therapeutic approach and pathological tumor stage. Results: The 5-year overall survival rate of patients with AC (37%; 95% confidence interval 25-49%) was remarkably higher compared to PDAC patients (7%; 95% confidence interval 5-10%). In both cohorts, surgical resection improved survival. Analysis of pathological factors revealed a survival benefit for patients staged with small primary tumors (pT1/2) and exclusion of distant metastases (M0) for both PDAC and AC. Interestingly, absence of lymph node metastasis substantially improved survival in AC, but not in PDAC. Conclusion: Overall survival of patients with AC is superior compared to that of patients with PDAC. Therapeutically, adequate regional lymph node dissection seems particularly important for the surgical management of AC.
- Pancreatic cancer
- pancreatic ductal adenocarcinoma
- ampullary carcinoma
- ampullary cancer
- survival
- prognosis
Death rates of many malignancies have decreased over the past decades, which can be attributed to the recent advances in cancer diagnostics and therapy. However, pancreatic cancer has not followed this trend, showing increasing death rates and a very poor overall 5-year survival rate of 5% (1, 2). Histologically, the vast majority of pancreatic carcinomas are adenocarcinomas arising from the ductal epithelial cells (PDAC). The only chance for cure for PDAC is complete surgical resection (3). However, this is only feasible when the malignancy is diagnosed at an early stage without infiltration of neighbouring tissue and is generally only considered when distant metastases are not detected. Therefore, only about 20% of all patients with PDAC are diagnosed at a stage where tumor resection can be considered with a curative intention. All remaining patients are diagnosed at an advanced, non-resectable tumor stage and consequently therapy remains palliative (4, 5). Two major factors have been suggested to account for the detrimental outcome of patients diagnosed with PDAC. Firstly, early diagnosis allowing curative resection of PDAC is often delayed due to non-specific symptoms. Secondly, PDAC is an exceptionally aggressive cancer entity that tends to exhibit early invasion and metastasis and, importantly, is commonly resistant to conventional radio- and chemotherapy (3). Thus, PDAC remains one of the major challenges in clinical oncology.
Malignant neoplasm of the ampulla of Vater, the shared outlet of the pancreatic and biliary duct, is a distinct tumor entity and referred to as ampullary carcinoma (AC). AC is in most cases an adenocarcinoma with heterogeneous origin arising either from the epithelial cells of the biliary or pancreatic duct (pancreatobiliary type), or from the duodenal mucosa (intestinal type) (6). Its incidence is lower than PDAC (7), but prognosis of patients diagnosed with AC is considered to be superior to that for PDAC (6, 8, 9). Due to their anatomical proximity, symptoms of PDAC and AC are similar, including abdominal pain, weight loss and jaundice caused by obstruction of the biliary duct. Similarly to PDAC, surgical resection provides the only chance for cure in patients with AC. For AC as well as for PDAC localized to the pancreatic head, partial pancreaticoduodenectomy is the surgical therapy of choice. For PDAC localized elsewhere than the pancreatic head, left pancreatectomy or total pancreatectomy are the standard surgical procedures (3, 6). In selected cases, local excision of an AC in terms of an ampullectomy can be performed as alternative to pancreaticoduodenectomy (10).
In summary, PDAC and AC are two gastrointestinal cancer entities originating from the pancreaticobiliary tract which share many similarities in symptoms, diagnosis and therapy, but, interestingly, are considered to differ regarding their respective prognoses.
Between January 1996 and December 2009, 505 patients diagnosed with PDAC and 69 patients diagnosed with AC underwent treatment in our Clinic. Patients underwent either cancer-directed surgery or palliative treatment, with or without palliative surgery. By performing a follow-up study of these patients, we analyzed side-by-side the outcome of patients in both cohorts and thereby aimed to identify important clinical and pathological factors affecting survival.
Patients and Methods
Patients and study design. Between January 1996 and December 2009, 559 patients with a pancreatic neoplasm and 73 patients with an ampullary neoplasm underwent treatment in our surgical Clinic. Among these, 505 patients were diagnosed with a PDAC and 69 patients with an AC. The remaining 58 patients were diagnosed with pancreatic tumors of non-adenocarcinoma histology or with neuroendocrine tumors and were subsequently excluded from the study. Of all 505 patients with PDAC, 258 (51%) were treated with a curative intent and underwent surgical resection. The remaining 247 patients with PDAC (49%) underwent palliative therapy without tumor resection. Out of all 69 patients with AC, the majority (63 patients; 91%) underwent surgical resection. The remaining six patients (9%) received palliative treatment.
Follow-up. All patients were enrolled in our tumor follow-up program, which included the evaluation of life status, tumor recurrence or progression, lymph node metastases, distant metastases, and overall response on a regular basis. Follow-up data were updated last on 30.6.2010 for all patients.
Data retrieval and documentation. Data were recorded in a prospective manner within our tumor follow-up program. The date of the primary surgery or begin of palliative therapy was used as the date of diagnosis. The age was calculated based on the day of diagnosis. Pathological features [primary tumor size (pT), tumor differentiation (grading), lymph node status (pN), existence of distant metastasis (pM) and Union for International Cancer Control (UICC) staging were obtained from histopathological reports of the resected tumor tissue at time of diagnosis.
Statistical analysis. Data about patients, treatment and follow-up data were collected using Microsoft Excel® and analyzed using SAS 9.3 (SAS Institute, Cary, NC, USA). Absolute and relative frequencies were calculated for qualitative variables. For quantitative variables, the median, minimum and maximum were calculated. The overall survival time was calculated from date of diagnosis to time of death or last observation date. The pathological tumor stage was characterized by pT, pN and incidence of pM. Based on TNM tumor stage, the comprehensive tumor stage defined by the UICC 7th edition (11) was determined. Lymph node ratio (LNR) was calculated as the ratio of tumor-affected lymph nodes to that of examined lymph nodes (12). The impact of the following factors on overall survival were analyzed: tumor entity, resectability, pT staging, pN staging, number of affected lymph nodes, LNR, pM staging, tumor grading and UICC tumor stage. Survival curves were plotted according to the Kaplan–Meier method and 5-year survival rates with a 95% confidence interval (CI) were calculated. In order to identify risk factors, Cox models were calculated. Results are given as hazard ratios (HR) together with the 95% CI and p-values.
Results
Patients' characteristics. A total of 505 patients diagnosed with PDAC and 69 patients diagnosed with AC were included in this study. Patients' characteristics are shown in Table I. In both patient groups the male gender was more prevalent: 57% of all PDAC patients and 59% of all AC patients. The median age at diagnosis was 65.3 (minimum 21.8-maximum 93.6) years and 66.1 (32.9-85.2) years for patients with PDAC, and AC, respectively. About half of all patients with PDAC underwent surgical resection with curative intention, whereas in patients with AC, the majority (91%) underwent resection and only 9% received palliative treatment (Table I). Of all patients with PDAC, the majority were diagnosed with a histopathologically-advanced primary tumor (pT3 and pT4) and existence of lymph node metastases (pN1). In contrast, most patients with AC were diagnosed with an early primary tumor stage (pT1 and pT2) and only in about half of all patients with AC were lymph node metastases (pN1) prevalent at the time of diagnosis. In the majority of patients with AC and PDAC enrolled in this study, distant metastases were clinically absent at the time of diagnosis and only a minority showed pathological evidence for distant metastases. Consequently, in the group of patients with AC, the pathological UICC stage I (defined by small primary tumor and absence of lymph node and distant metastases) was more prevalent compared to PDAC. When comparing these figures, it should be taken into account that for a relatively large number of patients with PDAC (but not AC), these criteria could not be determined due to a larger proportion of palliatively-treated patients in the PDAC cohort.
Overall survival of patients diagnosed with PDAC and AC and impact of surgical resection. At the time point when life status was updated, 429 of all patients with PDAC (85%) had died, 56 patients (11%) were alive, and for 20 patients (4%), life status was lost during follow-up. Out of all patients with AC, 42 patients (61%) had died, 21 patients (30%) were alive and life-status was lost during follow-up for 6 patients (9%). The median follow-up time was 11 months for PDAC (minimum of 0 - maximum of 172 months) and 32 months for AC (0-165 months). We set out to compare the survival of patients with PDAC to those diagnosed with AC. The overall survival of the PDAC group was poor, with a 5-year survival rate of 7% (95% CI 5-10%) and considerably lower than the survival of patients with AC, which was 37% (95% CI 25-49%) (Figure 1A). Next, we analyzed survival of patients who underwent surgical resection compared to those that received palliative treatment. For both AC and PDAC, survival at five years after diagnosis in the palliative treatment group was less than 1%. However, the 5-year overall survival rate after tumor resection amounted to 14% (95% CI 9-19%) in the PDAC group (Figure 1B) and 41% (95% CI 28–53%) in the AC group (Figure 1C).
Patients' characteristics.
Crude hazard ratios (HR) for overall survival with 95% confidence interval (CI).
Univariate analysis did not show any impact of age or gender on survival for PDAC or AC (Table II). In contrast and in line with above outlined 5-year survival rates, palliative treatment had a significantly higher risk of death compared to the patient cohort that received cancer-directed surgery for PDAC (HR 3.3; 95% CI 2.7-4.1) and even more evident for AC (HR 21.4; 95% CI 6.2-74.0) (Table II).
Impact of the pathological tumor stage and grading on survival of patients with PDAC, and AC. Next, the impact of the pathological tumor stage on survival was analyzed side-by-side for PDAC and AC, evaluating pT, pN and pM. The 5-year overall survival rate of patients with PDAC staged as pT1/2 was 23% (95% CI 12-36%) compared to a 5-year overall survival rate of 10% (95% CI 6-15%) in case of pT3/4 (Figure 2A). In the AC cohort, the 5-year overall survival rate of pT1/2 staged patients amounted to 45% (95% CI 27–61%), which was superior to the 5-year overall survival rate of 29% (95% CI 12-47%) in patients with pT3/4-staged tumors (Figure 2A). We went on and analyzed the impact of the existence of lymph node metastases. In patients with PDAC, detection of lymph node metastases in the pathological analysis only marginally affected the 5-year survival rate of 18% (95% CI 10-29%) for pN0-staged patients compared to 10% (95% CI 6-15%) for pN1-staged patients. In contrast in AC, pN0 was associated with a 5-year survival rate of 68% (95% CI 44-83%) compared to 21% (95% CI 9-36%) for pN1-staged patients (Figure 2B). In cases where distant metastases were clinically detected (cM0), the 5-year overall survival rate of patients with PDAC was 13% (95% CI 9-19%). In contrast, all patients diagnosed with distant metastases (cM1) died before the third year of follow-up (Figure 2C). Similarly to the PDAC cohort, all patients with AC diagnosed with distant metastases died within three years after diagnosis. In contrast M0-staged patients with AC had a 5-year survival rate of 38% (95% CI 24-52%). The pathological UICC tumor stage integrates tumor size, lymph node and distant metastases staging. In line with the aforementioned results, patients staged with UICC III or IV disease had an impaired 5-year survival rate compared to patients with UICC I and II stage disease for both PDAC and AC (Figure 3A).
Overall survival of patients with pancreatic ductal adenocarcinoma (PDAC) and ampullary cancer (AC) and impact of surgical resection. A: Kaplan–Meier curves showing overall survival for patients with PDAC (blue curve; n=505) compared to those with AC (red curve; n=69). The 5-year overall survival rates were 7% (95% confidence interval (CI) 5-10%) for PDAC and 37% (95% CI 25-49%) for AC. B: The plot depicts the overall survival for patients with PDAC undergoing curative treatment (blue curve; N=258) and palliative treatment (red curve; N=247). The 5-year overall survival rates were 14% (95% CI 9-19%) for patients undergoing curative treatment and <1% (95% CI 0-3%) for those receiving palliative treatment. C: The plot depicts the overall survival for patients with AC undergoing curative treatment (blue curve; N=63) and palliative treatment (red curve; N=6). The 5-year overall survival rates were 41% (95% CI 28-53%) for patients undergoing curative treatment and no patient who had been receiving palliative treatment was alive at this time point.
Next, we set out to identify important risk factors by univariate analysis site-by-site for AC and PDAC. A large primary tumor (pT3/4) was associated with a slight, but significantly higher risk of death for both PDAC (HR 1.4; 95% CI 1.0-2.0) and AC (HR 2.3; 95% CI 1.2-4.4) (Table II). Existence of lymph node metastases (pN1) was associated with a minimally higher risk of death in patients with PDAC (HR 1.6; 95% CI 1.2-2.1). In contrast, in patients with AC, the presence of lymph node metastases (pN1) increased the risk of death by 4-fold (95% CI 1.9-8.5). Evidence for distant metastases was a significant and one of the strongest survival-affecting factors in the PDAC and AC patient cohorts (HR of 3.9, 95% CI 2.8-5.4 for PDAC; HR 10.3, 95% CI 3.9-27.7 for AC). Analysis of the UICC stage revealed that a UICC stage III/IV was a significant predictor for death in both AC and PDAC. Regarding the grading of the tumor, a less-differentiated classified tumor (G3/G4) predicted a slightly poorer prognosis compared to a more differentiated tumor (G1/G2), with an HR of 1.9 for both AC and PDAC, which was, however, only statistically significant in the PDAC cohort.
Impact of pathological tumor stage (pTNM) on survival of patients with pancreatic ductal adenocarcinoma (PDAC) and ampullary cancer (AC). A: Kaplan–Meier curves showing overall survival for cohorts grouped according to the pathological T stage in PDAC (left panel) and AC (right panel). Histopathologically staged pT1/2 tumor (blue curve; N=49 for PDAC and N=35 for AC) were compared to pT3/4-staged tumors (red curve; N=229 for PDAC and N=24 for AC). The 5-year overall survival rate for patients with pT1/2 stage disease was 23% (95% confidence interval (CI) 12-36%) for PDAC and 45% (95% CI 27-61%) for AC and for those with pT3/4 was 10% (95% CI 6-15%) for PDAC and 29% (95% CI 12-47%) for AC. B: The plots depict overall survival for cohorts grouped according to the pathological N stage in PDAC (left panel) and AC (right panel). Patients with histopathologically staged pN0 (blue curve; N=85 for PDAC and N=26 for AC) disease were compared to those with pN1 disease (red curve; N=193 for PDAC and N=33 for AC). The 5-year overall survival rate for those with pN0 was 18% (95% CI 10-29%) for PDAC and 68% (95% CI 44-83%) for AC, and that for those with pN1 was 10% (95% CI 6-15%) for PDAC and 21% (95% CI 9-36%) for AC. C: The plots depict overall survival for cohorts grouped according to the pathological M stage in PDAC patients (left panel) or AC patients (right panel). cM0 (clinically, no evidence for distant metastasis - blue curve; N=219 for PDAC and N=48 for AC) was compared to pM1 (histopathological evidence of distant metastases - red curve; N=62 for PDAC and N=7 for AC). The 5-year overall survival rate for cM0-staged patients was 13% (95% CI 9-19%) for PDAC and 38% (95% CI 24-52%) for AC. No pM1-staged patient was alive at this time point for both PDAC and AC.
Impact of tumor grading and pathological UICC tumor stage on survival of patients with pancreatic ductal adenocarcinoma (PDAC) and ampullary cancer (AC). A: Kaplan-Meier curves showing overall-survival for cohorts grouped according to the pathological UICC tumor stage in patients with PDAC (left panel) and AC (right panel). Patients with UICC I staged tumors (blue curve; N=25 for PDAC and N=21 for AC) were compared to patients with UICC II staged tumors (red curve; N=206 for PDAC and N=29 for AC) and to patients with UICC III+IV staged tumors (green curve; n=81 for PDAC and n=12 for AC). The 5-year overall survival rate for patients with UICC I stage disease was 28% (95% confidence interval (CI) 11-48%) for PDAC and 64% (95% CI 37%-82%) for AC. The 5-year overall survival rate for patients with UICC II stage disease was 13% (95% CI 9%-19%) for PDAC and 27% (95% CI 12-44%) for AC. 5-year overall survival rate for patients with UICC III+IV stage disease was 0% for PDAC and 17% (95% CI 3-41%) for AC. B: The plots depict overall-survival for cohorts grouped according to tumor grading in patients with PDAC (left panel) and AC (right panel). Patients with highly differentiated tumors (G1- and G2-graded tumors - blue curve; n=215 for PDAC and N=47 for AC) were compared to those with poorly differentiated tumors (G3- and G4-graded tumors - red curve; N=147 for PDAC and N=15 for AC). The 5-year overall survival rate for patients with G1/2 graded tumors was 11% (95% CI 7-17%) for PDAC and 44% (95% CI=29-59%) for AC. The 5-year overall survival rate for patients with G3/4-graded tumors was 6% (95% CI 2-10%) for PDAC and 18% (95% CI 3-41%) for AC.
In summary, the 5-year overall survival rate of patients with AC was overall higher compared to PDAC patients in all sub-groups, except for the group where distant metastasis was detected. In this case, all patients diagnosed with AC or PDAC died within three years after diagnosis. Moreover, a large primary tumor, the histopathological detection of lymph node and distant metastasis and consequently an advanced UICC tumor stage was associated with impaired survival for both AC and PDAC.
Impact of number of affected lymph nodes and LNR on survival of patients with pancreatic ductal adenocarcinoma (PDAC) and ampullary cancer (AC). A: Kaplan-Meier curves showing overall-survival for cohorts grouped according to number of metastatic affected lymph nodes in patients with PDAC (left panel) and AC (right panel). The overall survival of patients diagnosed with 0 affected lymph nodes (blue curve; N=121 for PDAC and N=26 for AC) was compared to survival of patients with 1-4 affected lymph nodes (red curve; N=120 for PDAC and N=24 for AC) and >4 affected lymph nodes (green curve; N=30 for PDAC and N=7 for AC). The 5-year overall survival rate for patients diagnosed with 0 affected lymph nodes was 17% (95% confidence interval (CI) 10-25%) for PDAC and 68% (95% CI 45-84%) for AC. The 5-year overall survival rate for patients diagnosed with 1-4 affected lymph nodes was 9% (95% CI 4-16%) for PDAC and 25% (95% CI 10-43%) for AC. The 5-year overall survival rate for patients diagnosed with >4 affected lymph nodes was 11% (95% CI=3-26%) for PDAC and 14% (95% CI=7-46%) for AC. B: The plots depict the overall survival for cohorts grouped according to lymph node ratio (LNR) in patients with PDAC (left panel) and AC (right panel). Patients diagnosed with a LNR of 0 (blue curve; N=119 for PDAC and N=24 for AC) were compared to patients diagnosed with a LNR of 1-20 (red curve; N=81 for PDAC and N=14 for AC) and to patients diagnosed with a LNR >20 (green curve; N=61 for PDAC and N=13 for AC). The 5-year overall survival rate for patients diagnosed with a LNR=0 was 15% (95% CI=8-23%) for PDAC and 71% (95% CI 46-86%) for AC. The 5-year overall survival rate for patients diagnosed with a LNR=1-20% was 10% (95% CI 4-19%) for PDAC and 36% (95% CI 13-59%) for AC. The 5-year overall survival rate for patients diagnosed with a LNR>20% was 10% (95% CI 4-20%) for PDAC and 8% (95% CI 5-29%) for AC.
Interestingly, our study revealed that detection of lymph node metastasis in the pathological examination had an substantial impact on survival in AC (HR 4.0) but not so strong an impact in PDAC, where a significant but only minor effect of the existence of lymph node metastasis was observed (HR 1.6). We, therefore, analyzed the number of affected lymph nodes and the LNR, which are both commonly used for the staging of gastrointestinal cancer in addition to the TNM and UICC classification. In patients with PDAC, these analyses revealed only a minor impact of the LNR and the number of affected lymph nodes on the 5-year overall survival rate. In contrast, however, a LNR >20% and the presence of more than four affected lymph nodes drastically impaired 5-year overall survival in patients with AC (Figure 4A and B). In line with these findings, univariate analysis revealed that for the AC cohort more than four affected lymph nodes (HR 9.1; 95% CI 3.3-25.4) and a LNR >20% (HR 7.2; 95% CI 2.8-18.5) were strong risk factors. In contrast, in the PDAC cohort, neither the number of affected lymph nodes nor the LNR significantly affected the risk of death.
Discussion
Despite the fact that PDAC and AC are two relatively rare carcinoma entities of the gastrointestinal tract, both play a major role in surgical oncology due to the fact that cure can only be achieved by complete surgical resection. In PDAC, patients with a potentially resectable cancer, usually defined by locally restricted primary tumor growth and absence of distant metastases, are known to comprise the minority in only about 20% of all patients (5). In the case of AC, the reported resection rates are remarkably higher, ranging from 40% to more than 90% (13). This may be attributable to the fact that due to their close proximity to the papilla, even small ACs lead to obstruction of the biliary duct, causing symptomatic jaundice. Consequently the tumor is often diagnosed at an earlier tumor stage (6). This hypothesis is also in line with reports that PDAC localized in the pancreatic head, which is more likely to develop symptomatic obstruction of the biliary duct, has a higher rate of resectability and consequently a better prognosis compared to PDAC localized in the pancreatic tail (14, 15). Due to the fact that our study was performed in a specialized surgical clinic, the resection rates for both groups were comparatively high, with 51% for PDAC and 91% for AC, respectively.
Our study compared the outcome of patients suffering from PDAC and AC. Of note, the results revealed that patients with PDAC demonstrate profoundly impaired survival compared to patients with AC. This finding is in line with already reported survival rates for AC and PDAC (8, 9, 16). Interestingly, for AC, a survival benefit was also found in comparison with cholangiocarcinoma, another periampullary cancer entity (17). For patients with PDAC, a 5-year overall survival rate of about 5% is assumed based on several studies (3, 18), which is consistent with 7% found in our study. For patients with AC, the reported 5-year overall survival rates range from 20% to 60% (6, 7, 13, 19-21), whereupon the largest study including 1,301 patients revealed a 5-year survival rate of 37% (13), which is the same as our 5-year overall survival rate. As mentioned above, it is reasonable that the higher resection rate of AC compared to PDAC accounts for the superior prognosis of AC.
Comparing patients curatively treated by surgical resection with patients who received palliative treatment showed a substantial survival benefit for patients that underwent cancer-directed surgery. This survival benefit was particularly evident in patients with AC. For this group, our study revealed a 5-year overall survival rate of 41% after surgical resection. All patients with AC receiving palliative treatment died within five years. A recent study performed by Choi and colleagues, discriminating patients with AC treated by curative or palliative surgery led to a similar result: The 5-year overall survival rate was 60% in the case of resection, whereas in the palliative treatment group, all patients died within five years after diagnosis (22). For patients with PDAC, our analysis revealed a 5-year overall survival rate of 14% for patients who underwent surgical resection (compared to less than 1% for the palliative treatment group). These numbers are consistent with the data of a large retrospective study performed by Sohn and colleagues. This study, which included 616 patients who underwent surgical resection, showed a 5-year overall survival rate of 17% (23).
Analysis of the pathological tumor stage-related survival revealed, in line with survival analysis of other authors, a large primary tumor (pT3/4), pN1 or pM1 significantly increased the risk of death (13, 22-27). Interestingly, the presence of distant metastases was one of the strongest risk factors for impaired survival for both AC and PDAC. In contrast, our study showed that in patients with PDAC, the presence of lymph node metastases had only a minimal impact on survival. Even more intriguingly, the presence of more than four affected lymph nodes or an LNR of >20% were strong and significant predictors for risk of death in AC. In contrast, neither of these factors were significantly associated with a higher risk of death in PDAC. Controversially, other studies have reported the existence lymph node metastases as an important predictor for survival for both PDAC and AC (22, 23). Furthermore, contradictory results have been reported about whether the LNR or the number of affected lymph nodes is the more meaningful predictor for survival of patients with PDAC. Some authors claim the LNR to be the stronger prognostic factor (12, 28). In contrast, others reported that the number of affected lymph nodes is more meaningful for prognosis (29). However, the results of our study show that the prevalence of lymph node metastasis in PDAC has only a marginally impact on survival, independently of the approach how to characterize lymph node metastasis. This is in strong contrast to AC where the existence of lymph node metastasis turned out to be a strong and significant predictor of survival. In this context, it has been controversially discussed for decades if extended lymphadenectomy instead of standard lymphadenectomy performed in combination with the tumor resection might enhance survival in PDAC. Today, four trials comparing extended versus standard lymphadenectomy have been performed which did not reveal a benefit for the extended lymphadenectomy (30). Therefore, the standard lymphadencetomy remains the standard procedure. The finding of our study that lymph node metastasis only impacted survival to a minimal extent in PDAC strongly supports this suggestion.
In summary, our results showed a significantly impaired overall survival of patients with PDAC compared to AC. Moreover, in both patient groups, surgical resection was associated with a benefit in survival; however, this benefit was more pronounced in AC. In addition, our results showed that a large primary tumor and existence of distant metastases predict a substantially poorer outcome in both PDAC and AC. However, the absence of lymph node metastases strongly improved the outcome of patients suffering from AC, but not PDAC. In conclusion these significant differences in prognosis should be taken into consideration for the therapeutic approach in AC and PDAC. In particular, patients with AC may benefit from complete and radical regional lymphadenectomy.
- Received February 11, 2014.
- Revision received April 19, 2014.
- Accepted April 22, 2014.
- Copyright© 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved
