# Family history of colon cancer - Category: chronic - Review status: reviewed (every claim checked against a document named on this page) - Sources: Colon Cancer Screening - StatPearls (NCBI Bookshelf NBK559064) - https://www.ncbi.nlm.nih.gov/books/NBK559064/ · ICPC-3 (WONCA International Classification of Primary Care, 3rd edition) class AP66.01 - condition scope only, no dose · No dose - referral pathway, no medicine given in primary care - Verified date: 2026-08 ## Verified against - No dose - referral pathway, no medicine given in primary care - Hereditary Nonpolyposis Colon Cancer (Lynch Syndrome) - disease-level clinical article (family-history-colon-cancer-full.txt) ## Treatment metadata - No drug therapy in primary care (Referral & Advice) ## Complete treatment card ```text FAMILY HISTORY OF COLON CANCER Sources: Colon Cancer Screening - StatPearls (NCBI Bookshelf NBK559064) - https://www.ncbi.nlm.nih.gov/books/NBK559064/ · ICPC-3 (WONCA International Classification of Primary Care, 3rd edition) class AP66.01 - condition scope only, no dose · No dose - referral pathway, no medicine given in primary care Review status: REVIEWED against No dose - referral pathway, no medicine given in primary care, Hereditary Nonpolyposis Colon Cancer (Lynch Syndrome) - disease- level clinical article (family-history-colon-cancer-full.txt) (2026-08) IS IT THIS? - reference only, to read alongside your own examination SYMPTOMS - what the patient reports (5) - A strong family pattern of colorectal or endometrial cancer, especially cases diagnosed before age 50 across several generations, is characteristic - A personal history of colorectal cancer diagnosed before 50, right-sided tumors, or more than one primary cancer is relevant - Colorectal cancer can show up as rectal bleeding, a change in bowel movements, abdominal pain, weight loss, or fatigue [abdominal pain · fatigue · rectal bleeding · weight loss] - Abnormal uterine bleeding, pelvic pain, or bloating in a woman can point to endometrial or ovarian involvement [abdominal distension · abdominal pain · abnormal uterine bleeding · pelvic pain] - Brain, urinary tract, biliary tract, stomach, or small-bowel tumors are among the other cancers linked to this syndrome SIGNS - what you find (5) - Chronic-illness signs such as anemia-related pallor, or wasting and weight loss, can appear in advanced disease [anaemia · muscle wasting · pallor · weight loss] - A palpable abdominal mass, organ enlargement, or ascites can be found on exam in advanced disease [abdominal mass · ascites] - Rectal exam may turn up a palpable mass or evidence of blood in the stool [bloody diarrhoea · diarrhoea] - Sebaceous skin tumors or keratoacanthomas on skin exam suggest the Muir-Torre variant of this syndrome - Uterine enlargement or an adnexal mass may turn up on gynecologic exam [pelvic mass] TESTS (6) - Screening for testing is guided by the Amsterdam II criteria or the revised Bethesda guidelines - Tumor testing uses immunohistochemistry for mismatch-repair proteins or PCR for microsatellite instability - Amsterdam II criteria call for more than 3 affected relatives across at least 2 generations, one a first-degree relative of the other two, with at least one case diagnosed before age 50 - The revised Bethesda guideline flags colorectal cancer diagnosed before age 50 for testing - Because test choice and interpretation are complex and the results affect the whole family, genetic counseling should come before germline testing - When staining shows the MLH1 protein is missing, checking for a BRAF mutation or promoter methylation helps tell a sporadic cancer from true HNPCC IF NOT THIS - what else fits (3) - Microsatellite instability from a spontaneous, non-inherited mutation can look the same and needs molecular workup to sort out - Cowden syndrome, MUTYH-associated polyposis, and familial adenomatous polyposis are other hereditary colorectal syndromes that need to be ruled out - Some affected families show incomplete penetrance, which can make carriers harder to spot from family history alone Source StatPearls "Hereditary Nonpolyposis Colon Cancer (Lynch Syndrome)" - disease-level clinical article Status traced to the source above 1. NO DRUG THERAPY IN PRIMARY CARE (REFERRAL & ADVICE) [1st line] Adult A risk factor, not a disease; the GP's role is to advise on earlier/more frequent colonoscopy screening and refer for it, not to prescribe. - Refer, with advice Peds Children follow the same pathway: recognise and refer. No primary-care medicine is implied. Source No dose - referral pathway, no medicine given in primary care Why A risk factor, not a disease; the GP's role is to advise on earlier/more frequent colonoscopy screening and refer for it, not to prescribe. Caution No medicine is prescribed for this in primary care - this entry is for recognition and referral. Anything given is decided by the service it is referred to. The red flag symptoms of colorectal cancer are rectal bleeding, changes in bowel habits, abdominal pain, and weight loss. RED FLAG - Multiple affected first-degree relatives, or a relative diagnosed under age 50; personal symptoms (rectal bleeding, a change in bowel habit, weight loss) need urgent work-up regardless of the family history. Prices are indicative (dataset snapshot 2026-06); verify with the pharmacy. ``` --- Dawaa Reference is a reference for prescribers, not a medical device, and does not replace clinical judgement. [Privacy policy](/privacy)