[Purpose] To clarify the roles of health care professionals in support groups comprising patients, their families, and health care professionals. [Method] With the approval of the director of the Association of Patients with Familial Adenomatous Polyposis（FAP）Patients and Their Families, a content analysis was performed on newsletters published by the association. [Results] To solve problems that cannot be solved only through information exchange among association members, intervention by health care professionals who have medical knowledge regarding FAP was necessary. The roles of health care professionals in support groups consisted of the following: （1） Helping patients and their families understand medical information, （2） Providing information to help patients understand their own medical and physical conditions, （3） Providing information about what patients should be aware of in their daily lives, （4） Referring patients to appropriate medical care, （5） Helping patients improve their selfcare ability, and （6） Presenting the results of relevant studies. [Discussion] An analysis of the roles that health care professionals played in support group activities for 10 years has revealed how medical knowledge is provided according to members’ individual needs. A future plan is to clarify indicators for determining whether group or individual intervention is preferable. It is also planned to use information about various group interventions as a resource when creating a handbook for FAP patients.
Progress in the study of molecular genetics has been revealed that cancer is also a disease of genes, and that some cancers are hereditary. Nowadays, genetic testing is carried out on hereditary cancer, and the patients along with their families are provided with genetic information. 5–10 ％ of all breast cancer can be attributed to one of several breast cancer familial syndromes, the most common of which is the hereditary breast and ovarian syndrome caused by deleterious mutations of the BRCA1 and BRCA2 tumor-suppressor genes. We executed the genetic counseling to foreign resident in Japan that hoped for the genetic testing and counseling of the BRCA1 and BRCA2. We learnt the necessity of the preparation regarding language, cultural context, and introductions of information resources for consulter of foreign resident in Japan.
Hereditary colorectal cancer is a category of colorectal cancer that is mainly caused by his or her genetic or hereditary factors （mutations）. Familial adenomatous polyposis （FAP） and Lynch syndrome （Hereditary non-polyposis colorectal cancer, HNPCC） are the main syndromes in the category. This paper described a simple and essential introduction to the care of hereditary colorectal cancer. We discussed how important it is for patients with hereditary colorectal cancer to keep in touch with medical care throughout life time and over their next generations. Sometimes it is the most difficulties. We referred to the meaning of hereditary tumor counseling and self help societies.
The author outlines clinical features of the colorectal cancers associated with hereditary non-polyposis colorectal cancer （HNPCC）. These features include the early age of onset, high frequency of multiple colorectal cancers and right-side colon cancer, relatively good prognosis and the probability of the patient’s poor response to anti-cancer drugs. With regard to surgical treatment, the potential benefit of preventive colectomy before onset or removal of a large part of colon during surgery for colorectal cancers has not been clarified yet. For prevention, persons with HNPCC should follow generally recommended lifestyle which decreases the risk of colorectal cancers based on evidence from epidemiological studies. To date, effective drugs for chemoprevention have not yet been identified. Annual screening colonoscopy is desirable for early detection of colorectal cancers in persons with HNPCC.
Some cases of endometrial cancer are associated with a familial tumor and are referred to as hereditary nonpolyposis colorectal cancer (HNPCC or Lynch syndrome). Such tumors are thought to be induced by germline mutation of the DNA mismatch repair (MMR) gene, but many aspects of the pathology of familial endometrial cancer are unclear and no effective screening method has been established. At present, about 0.5–2.0% of all cases of endometrial cancers meet the clinical diagnostic criteria for HNPCC. A recent analysis of the three MMR genes (hMLH1, hMSH2 and hMSH6) revealed germline mutations in 18 of 120 cases (15.0%) of endometrial cancer with familial accumulation of cancer or double cancer, with a frameshift mutation of the hMSH6 gene being the most common. Many cases with mutation did not meet the current clinical diagnostic criteria for HNPCC, indicating that familial endometrial cancer is often not diagnosed as HNPCC. The results suggest that the hMSH6 gene mutation may be important in carcinogenesis in endometrial cancer and germline mutations of the MMR gene may be more prevalent in cases associated with familial accumulation of cancer.
Hereditary nonpolyposis colorectal cancer （HNPCC） is an autosomal dominantly in herited disorder showing predisposition to primary cancers from the colorectum, endometrium and other organs. HNPCC is estimated to account for 2 〜5% of all colorectal cancers and one of the most frequent cancer prone syndromes. Disruption of a mismatch repair system is associated with mictosatellite instability（MSI）in tumor tissues and germline mutations of mismatch repair genes such as MSH2 and MLH1 are observed frequently in the HNPCC kindred. As colorectal cancers are not the only one, but many other tumors comprise HNPCC-related tumors, the name “Lynch syndrome” was proposed for cases showing strong evidence of MMR deficiency, e.g., the presence of MMR defect or the presence of MSI in tumors. The name Lynch syndrome is derived from Henry T. Lynch, who discovered the existence of HNPCC or cancer family syndrome in the 1960s.
Most common diseases develop through complex interactions among multiple genetic factors and nongenetic （e.g. environmental） factors. Identifying the susceptibility genes has been difficult, because, unlike Mendelian diseases, each causal gene makes a small contribution to the pathogenesis of a disease. Genome wide association study （GWAS） is known as a potentially powerful approach for common complex diseases. Recently, many GWASs have been carried out to detect such causal genes. Here we briefly outline the basic concepts of GWAS and introduce our first experience, from which the PSCA gene was detected as a susceptibility gene of the diffuse type gastric cancer.