Outcome after multiple colorectal tumours

Synchronous colorectal cancer: Clinical, pathological and molecular implications

Synchronous colorectal carcinoma refers to more than one primary colorectal carcinoma detected in a single patient at initial presentation. A literature review has shown that the prevalence of the disease is approximately 3.5% of all colorectal carcinomas. This disease has a male to female ratio of 1.8:1. The mean age at presentation of patients with synchronous colorectal cancer is in the early half of the seventh decade. Patients with inflammatory bowel diseases (ulcerative colitis and Crohn’s disease), hereditary non-polyposis colorectal cancer, familial adenomatous polyposis and serrated polyps/hyperplastic polyposis are known to have a higher risk of synchronous colorectal carcinoma. These predisposing factors account for slightly more than 10% of synchronous colorectal carcinomas. Synchronous colorectal carcinoma is more common in the right colon when compared to solitary colorectal cancer. On pathological examination, some synchronous colorectal carcinomas are mucinous adenocarcinomas. They are usually associated with adenomas and metachronous colorectal carcinomas. Most of the patients with synchronous colorectal cancer have two carcinomas but up to six have been reported in one patient. Patients with synchronous colorectal carcinoma have a higher proportion of microsatellite instability cancer than patients with a solitary colorectal carcinoma. Also, limited data have revealed that in many synchronous colorectal carcinomas, carcinomas in the same patient have different patterns of microsatellite instability status, p53 mutation and K-ras mutation. Overall, the prognosis of patients with synchronous colorectal carcinoma is not significantly different from that in patients with solitary colorectal carcinoma, although a marginally better prognosis has been reported in patients with synchronous colorectal carcinoma in some series. A different management approach and long-term clinical follow-up are recommended for some patients with synchronous colorectal cancer.

Metachronous carcinomas in colorectum and its clinicopathological significance

PURPOSE

The study was designed to examine the significance of colorectal metachronous carcinoma in a large cohort of patients.

METHODS

Over a mean follow-up period of 10 years, the clinicopathological features, microsatellite instability (MSI) and clinical follow-up of 56 patients with metachronous colorectal carcinoma were analysed.

RESULTS

The prevalence of metachronous colorectal carcinoma was 2.1 %. The metachronous colorectal carcinomas appeared between 7 and 246 months (mean = 66 months) after surgical resection of the index colorectal carcinomas. Thirty-six per cent (n = 20) of the metachronous carcinoma occurred more than 5 years after the operation of the index carcinoma. Of the 56 patients, 20 % (n = 11) of the metachronous colorectal carcinomas were mucinous adenocarcinoma. Cancers detected in the secondary operations (metachronous colorectal carcinomas), when compared with the primary index cancers, were smaller, showed higher proportions of mucinous adenocarcinoma and more often located in the proximal colon. Patients with metachronous colorectal cancers had higher prevalence of mucinous adenocarcinoma, loss of staining for MSI markers and better survival rates than other patients with colorectal cancers.

CONCLUSIONS

Patients with metachronous colorectal carcinomas have characteristic features, and attention to these features is important for better management of this group of cancer.

Proximal location of colon cancer is a risk factor for development of metachronous colorectal cancer: a population-based study

PURPOSE

This study was undertaken to assess the incidence of 1) metachronous colorectal cancer and 2) subsequent extracolonic cancers, in relation to the location (proximal or distal to the splenic flexure) of the first primary colorectal tumor.

METHODS

In this population-based study, a cancer registry database was used to identify patients diagnosed with colorectal adenocarcinoma between 1970 and 1999. Patients with familial adenomatous polyposis and those with hereditary nonpolyposis colorectal cancer syndrome were excluded from the study, as were patients with nonepithelial tumors. Location of the first tumor was established according to International Classification of Diseases-Oncology-02 classification. The registry covers a population of 500,000 residents.

RESULTS

A total of 5,006 patients had sporadic adenocarcinoma of the colon or rectum during this period of time, with 1,703 first primary tumors (34 percent) being located proximal to the splenic flexure. One hundred twenty occurrences of second primary colorectal cancer were observed in this population (2.39 percent). The risk for developing a second incidence of primary colorectal cancer was higher in patients whose initial tumor was located in the proximal colon (3.4 percent vs. 1.8 percent; odds ratio, 1.92; 95 percent confidence interval, 1.33-2.77; P < 0.001). The risk for each segment of the large bowel was as follows: cecum, 3.4 percent; right colon, 3 percent; transverse colon, 3.8 percent; left colon, 2.8 percent; sigmoid colon, 1.7 percent; and rectum, 1.8 percent. By contrast, the risk for developing a second, extracolonic tumor did not differ between patients with proximal and distal tumors (13.7 percent vs. 13.4 percent, P = 0.73).

CONCLUSION

Patients with a first tumor located within the proximal colon are at twice the risk for developing metachronous colorectal cancer. From an epidemiologic standpoint, these data are in accordance with 1) the increasing incidence and 2) the better prognosis of proximal colon cancer in various populations. Our results confirm that proximal colon cancer is a distinct entity, which justifies the reporting of cases of colon cancer according to their location proximal or distal to the splenic flexure.

Follow-up strategies after curative resection of colorectal cancer

Consensus is lacking as to the best strategy for following patients who have undergone definitive surgical medical treatment for colon cancer. The goal of any surveillance program should be detection of recurrent disease at a sufficiently early time to allow subsequent curative therapy. Although periodic clinical examinations, laboratory tests, radiographic imaging, and carcinoembryonic antigen (CEA) testing have been utilized as a form of surveillance, such aggressive and costly intervention has not been validated through clinical studies. Four of the five randomized trials comparing such an intensive surveillance strategy to less frequent testing have not demonstrated the intensive approach to lead to an improvement in overall survival. Furthermore, intensive testing is both costly and has been shown not to improve quality of life. Further research designing appropriate postoperative testing is needed to guide physicians and patients after the curative resection of a colorectal cancer.

[Colonoscopic follow-up of patients undergoing curative resection of colorectal cancer]

AIM

To investigate the role of colonoscopy in the follow-up of patients undergoing curative resection of colorectal cancer.

MATERIAL AND METHODS

A prospective study was performed of 102 patients with colorectal cancer who underwent surgery with curative intention. Postoperative colonoscopic follow-up was a minimum of 5 years.

RESULTS

There were 62 males and 40 females. The mean duration of follow-up was 73.4 months. Synchronous polyps were found in 44.1% (114 in 45 patients) and metachronous polyps in 33.4% (64 in 34 patients). Synchronous carcinoma was detected in 7.8% (9 in 8 patients), metachronous carcinoma in 1.9% (2 in 2 patients) and suture recurrence in 4.9% (5 in 5 patients). Metachronous polyps developed in 55.5% of the patients with synchronous polyps and in only 15.8% of those with no synchronous polyps (p < 0.00005); the odds ratio was 6.67. Colonoscopy diagnosed 92 synchronous polyps and 64 metachronous polyps; of these, 34 were found to be significant(in 22 patients). Colonoscopy diagnosed 5 synchronous carcinomas; in 3 of these (polyps with non-invasive carcinoma) polypectomy constituted definitive therapy and in the remaining 2, curative resection was achieved. Colonoscopy diagnosed 2 stage C2 metachronous carcinomas at 63 and 94 months. Curative resection was achieved in both cases. Colonoscopic follow-up diagnosed 2 suture recurrences and resection was potentially curative.

CONCLUSIONS

Colonoscopy was found to play an essential role in 30% of the patients. The technique allowed the early diagnosis of synchronous carcinomas and curative treatment of metachronous carcinomas and demonstrated that the presence of synchronous polyps increases the risk of developing metachronous polyps.