The curative management of synchronous rectal and prostate cancer.

Objective: Neoadjuvant " long-course" chemoradiation is considered a standard of care in locally advanced rectal cancer. In addition to prostatectomy, external beam radiotherapy and brachytherapy with or without androgen suppression (AS) are well established in prostate cancer management. A retrospective review of ten cases was completed to explore the feasibility and safety of applying these standards in patients with dual pathology. To our knowledge, this is the largest case series of synchronous rectal and prostate cancers treated with curative intent. Methods: Eligible patients had synchronous histologically proven locally advanced rectal cancer (defined as cT3- 4Nx; cTxNl-2) and non-metastatic prostate cancer (pelvic nodal disease permissible). Curative treatment was delivered to both sites simultaneously. Follow-up was as per institutional guidelines. Acute and late toxicities were reviewed, and a literature search performed. Results: Pelvic external beam radiotherapy (RT) 45-50.4 Gy was delivered concurrent with 5-fluorouracil (5FU). Prostate total dose ranged from 70.0 to 79.2 Gy. No acute toxicities occurred, excluding AS-induced erectile dysfunction. Nine patients proceeded to surgery, and one was managed expectantly. Three relapsed with metastatic colorectal cancer, two with metastatic prostate cancer. Five patients have no evidence of recurrence, and fou r remain alive w ith metastatic disease. With a median follow -u p of 2.2 years (range 1.2-6.3 years), tw o significant late toxicities occurred; G3 pro c titis in a patient receiving palliative bevacizumab and a G3 anastomotic s tricture precluding stoma reversal. Conclusion: Patients proceeding to synchronous radical treatment of both primary sites should receive 45-50.4 Gy pelvic RT with infusional 5FU. Prostate dose escalation should be given with due consideration to the potential impact of prostate cancer on patient survival, as increasing dose may result in significant late morbidity. Review of published series explores the possibility of prostate brachytherapy as an alternative method of boost delivery. Frequent use of bevacizumab in metastatic rectal cancer may compound late rectal morbidity in this cohort. Advances in knowledge: To our knowledge, this is the largest case series of synchronous rectal and prostate cancers treated with curative intent. This article con trib utes to the understanding of how best to approach definitive treatment in these patients. [ABSTRACT FROM AUTHOR]