Comprehensive image features were extracted from CT and PET SUV images within manually delineated gross tumor volume, including geometry features, intensity features and texture features. The difference of feature values between two time points were also computed and analyzed. The area under the receiver operating characteristic ROC curve AUC was used to evaluate the accuracy of the prediction. In univariate analysis, six geometry, three intensity, and six texture features were identified as significant predictors of tumor recurrence. Anal cancer is a relatively uncommon malignancy. In the United States, the National Cancer Institute estimated 8, new cases and 1, deaths from anal cancer in 1. Chemoradiation therapy CRT is preferred over abdominoperineal resection for the treatment of anal cancer patients because of sphincter preservation, although surgery can be an effective salvage option 1 — 4.

Due to the low incidence of anal cancer and generally high cure rates, few second-line treatment options have been evaluated in the setting of formal clinical trials. We briefly report two cases that were both found to have wild-type K-RAS, with no epidermal growth factor receptor amplification or evidence of prior persistent human papilloma virus infection. Both cases were treated with irinotecan and cetuximab with evidence of clinical benefit in the setting of a third recurrence, as well as evidence of response to other strategies employed in their management. These cases provide support for the suggestion that treatment planning in conjunction with molecular profiling may be beneficial in such uncommon clinical settings.

The anus is the opening at the end of the digestive tract, below the rectum. It is where the end of the intestines connect to the outside of the body, and where stool bowel movements exit the body. Muscles within the anal canal and anus control the passage of stool from the rectum to outside the body. However, this is not true in other parts of the world.