eP683 - An Uncommon Cancer: Management of a Case of Rectal Squamous Cell Carcinoma

Purpose/Background: Squamous cell cancers account for 0.3% of all rectal cancers. No randomized control trials have been conducted given the low incidence. Historically, these cancers have been treated similarly to anal squamous cell carcinomas. The purpose of this study is to illustrate successful management of this unusual cancer in a community setting.Methods/Interventions: A sixty-six year old female living in rural Colorado was incidentally found to have a 4 x 5cm rectal mass on an MRI for new onset hip pain. Colonoscopy was completed and showed a rectal mass 15 cm from the anal verge. Biopsies were notable for a poorly differentiated squamous cell carcinoma of the rectum. A second flexible sigmoidoscopy by colorectal surgery confirmed a partially circumferential 5cm x 6cm fungating rectal mass at 15 cm. Repeat biopsies confirmed the pathology. MRI pelvis showed extension into the left posterolateral mesorectal, abutment of the peritoneal reflection and left piriformis, and enlarged mesorectal lymph nodes. PET/CT showed no distant metastases; her stage was therefore Stage 3B (cT3, cN2a, cM0) rectal cancer.Results/Outcomes: This patient’s case was discussed at a multidisciplinary tumor board in an urban community hospital. After consultations with medical, surgical, and radiation oncology as well as colorectal surgery, the decision was made to treat her with the modified Nigro protocol which included mitomycin-C on days 1 and 29 and capecitabine 825mg twice daily (M-F) for 6 weeks concurrently with 27 fractions of radiation to a total of 4509 cGy. Flexible sigmoidoscopy at 8 weeks after completion of chemoradiation showed an area of rectal anterior wall necrosis and ulceration from 10-15 cm. PET at this time showed some uptake at the rectum but decreased size of mesorectal lymph nodes, and MRI showed significantly reduced tumor size and number of nodes. A second flexible sigmoidoscopy 14 weeks after treatment completion showed a solitary 7 mm ulcer at the mid rectum. Biopsy revealed ulcerated colonic mucosa with granulation tissue and no evidence of malignancy. Continued surveillance with flexible sigmoidoscopy every 12 weeks is planned with repeat imaging in 12 weeks and then every 6 months.Conclusion/

Discussion: This case report outlines successful management of a rectal squamous cell carcinoma with the modified Nigro protocol in a community setting. It highlights the quality of multidisciplinary cooperation in the community setting and the importance of treatment design based on available literature for an uncommon malignancy."Pretreatment Sigmoidoscopy

Fungating rectal mass from 10-15 cm
Post Treatment Sigmoidoscopy

Anterior wall necrosis from 10-15 cm, 8 weeks post treatment
Post Treatment Sigmoidoscopy

Solitary 7 mm ulcer at 14 weeks post treatment
Pre Treatment MRI
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