Radiation-induced Second Malignancies

Case Scenarios

Table II lists some cases seen by the authors. All second malignancies in the Table are within previous radiation field. Both previous radiation doses and time intervals to second malignancies vary greatly.

The first patient in Table II was diagnosed in 2005 with adenocarcinoma of the left breast, stage T1 N1. She underwent lumpectomy and axillary dissection. One out of twenty-two nodes were involved. It was a T1 tumor, grade 2. Lymphovascular invasion was negative. The tumor was estrogen- and progesterone receptor-positive. The patient received adjuvant external beam radiotherapy in 2005 with a dose of 50 Gy in 25 fractions to the entire left breast by a 6 MV photon and a 12 MeV electron boost of 10 Gy in 5 fractions to the lumpectomy site. She also received adjuvant tamoxifen. The patient remained well after that for eight years. In the winter of 2012, she started to notice some purplish discoloration of the skin of the lower half of the left breast. A biopsy showed angiosarcoma. She underwent investigations included CT scan of the chest, abdomen and pelvis showing skin thickening in the left breast with an approximately 2 cm spiculated mass involving the left breast tissue laterally. There was a 6-mm pulmonary nodule seen at the left base peripherally, as well as a few other tiny subpleural nodular densities. These were entirely nonspecific at that point but could be assessed on follow-up. There was no lymphadenopathy. The intra-abdominal solid organs were normal in appearance. The tumor had grown in the last six months. Upon examination, the left breast was tender only on palpation and it was not painful, usually for the patient. A wide local excision of the tumor was performed on November 12, 2013 and no graft was required at that time. The lesion was grossly removed but the superior margin was less than 0.5 mm. The surgeon performed a re-resection. Four months later she developed multiple bone metastases involving the cervical spine and received palliative radiotherapy 20 Gy in 5 fractions. She died five months after diagnosis of angiosarcoma.

The second patient had a Hodgkin's lymphoma in 1981 when he was 16 years of age, treated with mantle and inverted-Y radiation to 35 Gy/20 fractions plus a boost of 5 Gy/2 fractions to the lower neck with a cobalt machine. He was well until 2002 when a high-grade papillary carcinoma, possibly insular carci noma, was found. A total thyroidectomy was performed in June 2002 followed by radioactive iodine ablation (30 mCi). He developed nodal recurrence and, hence, a right neck dissection was performed in November 2002. He then developed an occipital skull metastasis with generous excision in January, 2005 followed by postoperative local radiotherapy 56 Gy/28 fractions as the patient was afraid of wide field radiotherapy to the whole skull or brain. He developed bilateral neck node recurrences and had bilateral neck dissection and right hemilaryngectomy in May 2005 in Toronto, followed by radioactive iodine therapy in Saskatoon in August 2005. He also completed 40 Gy/25 fractions in May 2006 to the upper and right lower neck. Later, he developed a left parasagittal brain metastasis and was treated by excision in January 2007. He then had a resection of a right cerebellar metastasis by mid-July 2007 and 50.4 Gy/28 fractions to the cerebellum. His surgery was complicated by respiratory distress requiring intubation and a tracheostomy tube was placed. Further recurrence occurred in the posterior fossa but no more radiation could be safely given. He expired at the age of 44 from the thyroid cancer.

The third patient was diagnosed with an adenocarcinoma of the prostate in May, 1997 at the age of 57. He had a radical prostatectomy and the distal margin was positive. He presented to the cancer clinic again in 2002 with a slowly rising PSA. There was no conclusive evidence of distant metastases. He completed salvage radiotherapy to pelvis 60 Gy/30 fractions on January 27, 2003. He started androgen deprivation therapy in March 2005 in an intermittent manner. By November 2007, he was found to have an early stage rectal adenocarcinoma and abdomino-perineal resection was performed. He did not require any adjuvant chemo therapy or radiotherapy. In March 2009, his PSA rose to 51.1 μg/l and bicalutamide was added to leuprolide. He also had four doses of zoledronic acid. He was put on fragmin due to pulmonary embolism. He then developed a low-grade neoplasm of bladder, treated surgically in February 2008. The patient became bed-ridden in the summer of 2009. He had repeated biopsies of a right groin mass and the conclusion was recurrent prostatic adenocarcinoma. He was started on docetaxel chemotherapy and had some initial improvement in the fact that the patient was able to walk again. Since October 2009, he started having pain in the right inguinal area, which was an 8 cm long×10 cm wide fixed metastatic mass in the lower anterior abdominal wall. There was some vague swelling above the pubic area. Palliative radiotherapy was arranged. As accurate as possible, the staff reproduced the previous treatment setup. The patient understood that a perfect reproduction of the previous treatment might not be feasible and occasionally some small bowel loops could move into the area and got retreated. He completed 30 Gy in 10 fractions to the upper pelvis and 20 Gy/10 fractions to the lower pelvis on 22 January 2010. The patient underwent radiation uneventfully. The radiation helped his pain. He died of metastatic prostate cancer at 70 years of age.