As tests evolve and costs of cancer care rise: reappraising stool-based screening for colorectal neoplasia

Value of symptoms and additional diagnostic tests for colorectal cancer in primary care: systematic review and meta-analysis

OBJECTIVE

To summarise available evidence on diagnostic tests that might help primary care physicians to identify patients with an increased risk for colorectal cancer among those consulting for non-acute lower abdominal symptoms.

DATA SOURCES

PubMed, Embase, and reference screening. Study eligibility criteria Studies were selected if the design was a diagnostic study; the patients were adults consulting because of non-acute lower abdominal symptoms; tests included signs, symptoms, blood tests, or faecal tests. Study appraisal and synthesis methods Two reviewers independently assessed quality with a modified version of the QUADAS tool and extracted data. We present diagnostic two by two tables and pooled estimates of sensitivity and specificity. We refrained from pooling when there was considerable clinical or statistical heterogeneity.

RESULTS

47 primary diagnostic studies were included. Sensitivity was consistently high for age >or=50 (range 0.81-0.96, median 0.91), a referral guideline (0.80-0.94, 0.92), and immunochemical faeces tests (0.70-1.00, 0.95). Of these, only specificity of the faeces tests was good. Specificity was consistently high for family history (0.75-0.98, 0.91), weight loss (0.72-0.96, 0.89), and iron deficiency anaemia (0.83-0.95, 0.92), but all tests lacked sensitivity. None of these six tests was (sufficiently) studied in primary care.

CONCLUSIONS

Although combinations of symptom and results of immunochemical faeces tests showed good diagnostic performance for colorectal cancer, evidence from primary care is lacking. High quality studies on their role in the diagnostic investigation of colorectal cancer in primary care are urgently needed.

Editorial: It's time to make organized colorectal cancer screening convenient and easy for patients

Colorectal cancer (CRC) screening is widely recommended, but underused. To increase screening rates, we need to implement organized and population-based systems to promote CRC screening among people in a single region, health plan, or health system. This is ideally accomplished using fecal immunochemical tests (FITs), which can be sent through a mass mailing. The study by Levi and colleagues shows that patients using aspirin, non-steroidal anti-inflammatory drugs (NSAIDs), anti-platelet agents, or anti-coagulants do not need to stop these medications while doing the fecal collection. This makes the testing more convenient for patients, and avoids the risk of adverse cardiovascular events caused by stopping these medications.

Colon cancer and the elderly: from screening to treatment in management of GI disease in the elderly

Colorectal cancer is one of the commonest tumours in the Westernized world affecting mainly the elderly. This neoplasm in older individuals occurs more often in the right colon and grows more rapidly than in the young, often shows a mucinous histology and mismatch repair gene changes. Effective screening permits discovery of colorectal cancer at an early highly treatable stage and allows for detection and removal of premalignant colorectal adenomas. Screening methods that focus on cancer detection use fecal assays for the presence of blood or altered DNA, those for detection of adenomas (and early cancer) use endoscopic or computerised radiologic techniques. Broad use of screening methods has lowered colorectal cancer development by about 50%. In addition, prevention of the earliest stage of colon carcinogenesis has been shown to be effective in small prospective studies and epidemiologic surveys but have not been employed in the general population. Since 1996 the chemotherapeutic armamentarium for metastatic colorectal cancer has grown beyond 5-fluorouracil to include an oral 5-fluorouracil prodrug, capecitabine as well as irinotecan and oxaliplatin. Three targeted monoclonal antibodies (Moabs), bevacizumab (an anti-vascular endothelial growth factor Moab) and cetuximab/panitumumab, both anti-epidermal growth factor receptor inhibitors, have also earned regulatory approval. Most stage IV patients are treated with all of these drugs over 2 or 3 sequential lines of palliative chemotherapy and attain median survivals approaching 24 months. Lastly, adjuvant oxaliplatin plus 5-fluorouracil for high risk resected stage II and stage III colon cancer patient has led to substantial improvement in cure rates. With appropriate care of age associated comorbidities these treatment modalities are feasible and effective in the geriatric population.