ABSTRACT

The development of synchronous gastric and colon cancers is particularly rare. When the increasing worldwide average life expectancy is taken into consideration, the increase in rate of synchronous and metachronous cancers is an expected situation. It is considered that a preoperative detailed investigation is required in patients with primary tumor in terms of synchronous and metachronous cancers. In this case report, we aimed to present the diagnostic and therapeutic methods in a patient with synchronous gastric and colon cancers.

Introduction

Multiple primary cancers develops simultaneously or consecutively, and independently from each other in the same patient, and the prevalence of multiple primary cancers varies in the ratio of 0.7% to 11.7% of all types of carcinomas in the medical literature.^1,2,3 In general, multiple primary cancers are divided into two groups; synchronous and metachronous. If the latter cancer is detected after 6 months of the first diagnosis, it is named as metachronous; or if it is detected within 6 months of the first diagnosis, it is named as synchronous cancer.⁴ Synchronous gastric and colon cancer are rare cancer types. The most common synchronous cancer is colorectal cancer in patients with gastric cancer.^5,6 In the present study, it was aimed to compare the treatment process of an operated patient with gastric and colon cancer with the literature data.

Discussion

The risk of development of secondary tumors in cases with primary tumors is 1.29 times higher in comparison to healthy individuals.⁷ Multiple primary tumors are more common in advanced-aged group (>65 years) in accordance with the age-classification of World Health Organization. Thus, aging is considered as a risk factor in cancer development. Aging-related weakness in immune system and low-resistance associated with carcinogen exposure might be the relevant causes.⁸ Although, any defect in DNA repair system might have a role in multiple cancer development, the reason of development of synchronous cancer still remains uncertain.⁹

The most common synchronous cancer among patients with gastric cancer is colorectal cancer, and the most common synchronous cancer among patients with colorectal cancer is gastric cancer. It is known well that the most common cancer is gastric cancer in patients with hereditary non-polyposis colorectal cancer, except colon cancer.¹⁰

In case of a synchronous cancer, as the prognosis of early-stage cancer is better than advanced-stage cancer and it might be affected from a synchronous cancer, surgical operations should be performed as synchronous as possible.^11,12 As average life expectancy worldwide has increased, an elevation in the ratio of synchronous and metachronous cancers is an expected result. A detailed pre-operation examination of patients with primary tumor is considered to be required in terms of synchronous and metachronous cancers.