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"Why do anal cancers spread so quickly?"


My husband has it and it is spreading fast. Is this typical? We're trying to contain it and get him better.


That's a tough question because there are different kinds of anal cancer. Because the anus is the junction between the "inside" of the body (columnar epithelium) and the "outside" of the body (squamous epithelium), the two most common kinds of anal cancer are squamous cell carcinoma (80%) and basaloid transitional cell carcinoma with adenocarcinoma and melanoma also possible. All of these tend to spread at different rates but on top of this, there are different characteristics even among those types.

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If your doctor has taken a biopsy of it, he will need to know if it is high grade poorly differentiated (spreads faster) or low grade well differentiated (spreads slower). The short answer is that everyone's anal cancer spreads at a different rate. Compared to some others, it is typically a slower growing cancer, especially if it is of the adenocarcinoma variety, but it is too individualized to make a blanket statement like that. Unfortunately you say that in your husband's case, his cancer is one that is rapidly growing. While about 90% of anal cancers are locally contained on presentation, some can be metastatic. The standard treatment for these cancers depends on where exactly it is. If the cancer is around the anus but not into the anal canal, then the surgical option of wide local excision is the treatment of choice if your doctor thinks they can get all of it. If it involves the anus and canal, then chemoradiation therapy is the treatment of choice using the Nigro Protocol of local radiation, 5-FU, mitomycin. Anal cancers tend to respond fairly well to this treatment without the need for more invasive surgery, however sometimes the cancer will fail to respond fully or will recur, in which case further surgical intervention will be required. I would ask your oncologist for more details about your husband's cancer (e.g. what stage and grade it is, what the pathology showed, what will be required for metastatic workup) so that you can decide together what the best course of initial action should be.

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