Complete Spontaneous Regression of Colorectal Cancer: A Report of Two Cases

Abstract

Spontaneous regression of cancer is rare, and rarer still in colorectal cancer. We present a report of two cases of spontaneous regression of histologically proven proximal colonic cancers described in detail, alongside endoscopic, histological, and radiological images. We discussed the potential mechanisms by reviewing previous literature.

Case Details

Disease Location

Colon

Personal Characteristics

78-year-old female, medical history of bladder cancer, total abdominal hysterectomy and bilateral salpingo-oophorectomy for endometriosis, congestive cardiac failure, hypertension, diet-controlled type 2 diabetes, chronic kidney disease (ckd) stage 3, and gout. She was an ex-smoker.

Clinical Characteristics

Urgent cancer referral basis with eight weeks of diarrhea, opening her bowels up to eight times a day. She lost 13 kg over the last six months. She had mild iron-deficient anemia. CT virtual colonoscopy showed a 2.2 cm eccentric segment of thickened mid-ascending colon suspicious of a neoplastic lesion. Colonoscopy revealed a 2.5 cm ulcerated lesion in the hepatic flexure which appeared to be malignant was identified and tattoos were placed distally at three places. Five biopsies were taken of the lesion. These suggested poorly differentiated carcinoma. She underwent an uneventful laparoscopic right hemicolectomy

Remission Characteristics

Histological examination showed a small focus on non-specific mucosal ulceration, with an inflammatory reaction extending into the muscularis propria. A few small mucin pools were noted within the muscularis propria at this point, but there was no evidence of dysplasia or invasive malignancy. 27 lymph nodes were identified, which were negative. There was no evidence of malignancy within the resected specimen.

Treatment & Mechanisms

Proposed Remission Mechanisms

Local trauma could have stimulated inflammation and an immune response, or it could be that the biopsies removed the only focus of cancer.

Clinical Treatment

Biopsy