Triple metachronous colon cancer

Abstract

A 72-year-old male with an early stage “node-negative” sigmoid colon cancer developed 2 separate “node-negative” early stage colon cancers during a subsequent colonoscopy surveillance regimen, the first in the descending colon 7 years later, and the second in the cecum almost 14 years after the first cancer was resected. After the initial symptomatic cancer, all subsequent neoplastic disease, including malignant cancers were completely asymptomatic. This entity, multiple primary cancers, likely reflected the use of a colonoscopic surveillance regimen.

Key Words: Colorectal cancer, Surveillance colonoscopy, Multiple primary cancer syndrome, Metachronous colorectal cancer

Core tip: Detection of increasing numbers of asymptomatic metachronous colon cancers may result from widening use of surveillance colonoscopy in patients with a previously treated early stage colon cancer.

TO THE EDITOR

An article recently published in the World Journal of Gastroenterology concerning a patient with quadruple malignancies involving different organ sites, but with survival over more than 20 years is rare (below 0.1%) and has special significance[1]. The authors suggest that the incidence of multiple primary cancers (MPC) is rising, possibly related to individual genetic susceptibility and other factors[1]. The patient described here below emphasizes that this rising incidence in MPC may also result from increasing use of surveillance colonoscopy regimens aimed at high risk groups, specifically those with early stage (“node-negative”) colon cancer.

A 72-year-old otherwise healthy male developed constipation and rectal bleeding in June 1997. Subsequent colonoscopic evaluation revealed a 4 cm ulcerated mass in the distal sigmoid colon. Anterior resection revealed a moderately differentiated adenocarcinoma invading just through the muscularis propria (T3). Lymph nodes were negative for malignancy with no lymphovascular invasion. Subsequent annual colonoscopies showed small tubular adenomas that were resected. In addition, biopsies of the prior anastomosis were negative. In 2004, additional tubular adenomas were resected and a diminutive ulcerated sessile polypoid lesion in the rectum revealed severely dysplastic mucosa. Because of the high suspicion for an invasive malignancy, another laparotomy was done. The previous anastomosis was resected and revealed no evidence for malignancy and a further resection of the descending colon was done revealing a second infiltrative moderately differentiated colonic adenocarcinoma measuring 1 cm in diameter and extending into the muscularis propria (T2). Lymph nodes were negative for malignancy with no lymphvascular invasion. Subsequent colonoscopies in 2004, 2005 and 2006 revealed diminutive tubular adenomas that were resected. In 2010, a further colonoscopy revealed a single small tubulovillous adenoma in the ascending colon that was removed. Another ulcerated polypoid lesion was detected in the cecum and biopsies confirmed a third moderately differentiated adenocarcinoma. Subsequent right hemicolectomy revealed extension through the muscularis propria with negative lymph nodes and no lymphovascular invasion (T3). In summary, despite 3 separate “node-negative” cancers, all treated by surgical resection alone, this patient remains well, now over 15 years. As a direct result of surveillance, the last 2 colon cancers were detected at an early and asymptomatic stage.

After complete resection of a colonic adenocarcinoma, colonoscopy guidelines recommend ongoing surveillance to exclude subsequent development of metachronous colon cancer[2]. A high intensity form of surveillance is often recommended for the initial 5 years[2]. In our experience, longer term colonoscopic surveillance after endoscopic removal of either malignant polyps[3] or more sessile early stage (“node-negative”) colon cancers[4] have also yielded significant numbers of patients with metachronous colon cancers, a specific form of MPC[1], at an early asymptomatic stage of the disease. This experience underlines the importance of colonoscopy surveillance of high risk categories, particularly prior colonic cancer patients with “node-negative” disease. With the expectation that these highly-selected patients will survive for extended periods, colonoscopic surveillance per se can be expected to yield increasing numbers of patients with colonic metachronous MPC in the future.