How would you treat a synchronous anal canal squamous cell carcinoma and localized high risk prostate adenocarcinoma?

The primary anal cancer and prostate cancer can be treated with a whole pelvic field to include the anus and prostate/SV (45-50 Gy) with a simultaneous integrated boost for the anal tumor (RTOG 0529). HDR brachytherapy can then be used to boost the prostate after a short recovery from the external beam therapy. Systemic therapy can be integrated, i.e. androgen deprivation therapy for the prostate cancer and Mitomycin-C and 5-FU/capecitabine for the anal cancer.

We use similar approaches for rect...

The approach suggested by Dr.@Dr. First Last is very thoughtful and I fully agree it would be an excellent treatment strategy.

I’ve cared for a handful of patients in this scenario as well with favorable toxicity/cancer control outcomes so I figure I’d throw my approach into the mix of options.

I generally use a simultaneous boost approach over 28 fractions. RTOG 0415 established 70 Gy in 28 fractions as a reasonable fractionation scheme for localized prostate cancer.

For the anal canal tumor, I ei...