The effect of time before diagnosis and treatment on colorectal cancer outcomes: systematic review and dose-response meta-analysis

BACKGROUND

This systematic review and meta-analysis aimed to evaluate existing evidence on the relationship between diagnostic and treatment intervals and outcomes for colorectal cancer.

METHODS

Four databases were searched for English language articles assessing the role of time before initial treatment in colorectal cancer on any outcome, including stage and survival. Two reviewers independently screened articles for inclusion and data were synthesised narratively. A dose-response meta-analysis was performed to examine the association between treatment interval and survival.

RESULTS

One hundred and thirty papers were included in the systematic review, eight were included in the meta-analysis. Forty-five different intervals were considered in the time from first symptom to treatment. The most common finding was of no association between the length of intervals on any outcome. The dose-response meta-analysis showed a U-shaped association between the treatment interval and overall survival with the nadir at 45 days.

CONCLUSION

The review found inconsistent, but mostly a lack of, association between interval length and colorectal cancer outcomes, but study design and quality were heterogeneous. Meta-analysis suggests survival becomes increasingly poorer for those commencing treatment more than 45 days after diagnosis.

REGISTRATION

This review was registered, and the protocol is available, in PROSPERO, the international database of systematic reviews, with the registration ID CRD42021255864.

A systematic review of methodological considerations in time to diagnosis and treatment in colorectal cancer research

Research focusing on timely diagnosis and treatment of colorectal cancer is necessary to improve outcomes for people with cancer. Previous attempts to consolidate research on time to diagnosis and treatment have noted varied methodological approaches and quality, limiting the comparability of findings. This systematic review was conducted to comprehensively assess the scope of methodological issues in this field and provide recommendations for future research. Eligible articles had to assess the role of any interval up to treatment, on any outcome in colorectal cancer, in English, with no limits on publication time. Four databases were searched (Ovid Medline, EMBASE, EMCARE and PsycInfo). Papers were screened by two independent reviewers using a two-stage process of title and abstract followed by full text review. In total, 130 papers were included and had data extracted on specific methodological and statistical features. Several methodological problems were identified across the evidence base. Common issues included arbitrary categorisation of intervals (n = 107, 83%), no adjustment for potential confounders (n = 65, 50%), and lack of justification for included covariates where there was adjustment (n = 40 of 65 papers that performed an adjusted analysis, 62%). Many articles introduced epidemiological biases such as immortal time bias (n = 37 of 80 papers that used survival as an outcome, 46%) and confounding by indication (n = 73, 56%), as well as other biases arising from inclusion of factors outside of their temporal sequence. However, determination of the full extent of these problems was hampered by insufficient reporting. Recommendations include avoiding artificial categorisation of intervals, ensuring bias has not been introduced due to out-of-sequence use of key events and increased use of theoretical frameworks to detect and reduce bias. The development of reporting guidelines and domain-specific risk of bias tools may aid in ensuring future research can reliably contribute to recommendations regarding optimal timing and strengthen the evidence base.

Time to diagnosis and stage of symptomatic colorectal cancer determined by three different sources of information: A population based retrospective study

BACKGROUND

Survival rates from colorectal cancer (CRC) are highly variable in Europe. This variability could potentially be explained by differences in healthcare system delays in diagnosis. However, even when such delays are reduced, the relationship of the diagnostic interval (time from presentation with symptoms to diagnosis) with outcome is uncertain.

METHODS

A total of 795 patients with CRC from 5 regions of Spain were retrospectively examined in this population-based multicenter study. Consecutive incident cases of CRC were identified from pathology services. The total diagnostic interval (TDI) was defined as the time from the first presentation with symptoms to diagnosis based on 3 different sources of information: (i) patient-recorded data (PR-TDI) by interview, (ii) hospital-recorded data (HR-TDI), and (iii) general practitioner-recorded data (GPR-TDI). Concordance correlation coefficients (CCCs) were used to estimate the agreement of 3 different TDIs. The TDIs of patients with different stages of CRC were also compared using the Kruskal-Wallis test.

RESULTS

The median TDI was 131days based on patient interview data, 91days based on HR data, and 111days based on GPR data. Overall, the agreement of these TDIs was poor (CCC_PRvsHR=0.399, CCC_PRvsGPR=0.518, CCC_HRvsGPR=0.383). Univariate analysis indicated that the TDI was greater in those with less advanced CRC for all 3 methods of calculation, but this association was only statistically significant for the HR-TDI (p=0.021).

CONCLUSION

There is no evidence that patients with more advanced CRC have longer TDIs. In fact, we found an inverse relationship between the TDI and CRC stage, an example of the "waiting time paradox". This association may likely be due to the presence of unmeasured confounders as the stage when symptoms appear or the tumour aggressiveness.

Medical malpractice claims in relation to colorectal malignancy in the national health service

AIM

Under the current increased financial constraints affecting the National Health Service (NHS), clinical negligence claims and associated compensations are constantly rising. Our aim was to identify the magnitude, trends and causes of malpractice claims in relation to a common pathology such as colorectal malignancy in the NHS.

METHOD

Data requests were submitted to the NHS Litigation Authority (NHSLA) and to the Medical Defence Union (MDU) and Medical Protection Society (MPS). Data were reviewed, categorized clinically and analysed in terms of causes and costs behind claims.

RESULTS

Data from the MPS and MDU were unavailable. In all, 169 claims were identified from the NHSLA database between 2003 and 2012; 123 (73%) cases had been closed, 80 (65%) of which were successful. An increasing overall claim frequency and success rate were found over the last few years. Total litigation expenses were £8.6 million, with 39% paid out as legal expenses. The commonest cause of complaint in successful claims was in relation to diagnostic delays or failures (58%, £5.1 million), with a delay or failure by the clinician to take action in response to an abnormal investigation result being a major factor. The occurrence of peri-operative complications (20%, £1.6 million) was the second commonest cause.

CONCLUSION

Average frequency and success rates of malpractice claims in secondary care in the NHS are rising, leading to significant overall payouts. The failure or delay in diagnosing colorectal malignancy or its postoperative complications is a common cause behind malpractice claims. Improvement in these areas could enhance patient care and reduce future claims.

Factors influencing diagnosis of colorectal cancer: a hospital-based survey in China

OBJECTIVE

To investigate the diagnostic status of colorectal cancer (CRC) and the influence of early diagnosis and cancer stage in a tertiary care hospital in China.

METHODS

Face-to-face interviews were conducted in 364 consecutive CRC patients who had never participated in CRC screening. Initial symptoms, diagnosis and treatment delay were determined using a questionnaire. Factors influencing diagnostic status were analyzed using univariate analysis and logistic regression model.

RESULTS

A total of 307 patients were enrolled, in which 128 were with colon cancer and 179 with rectal cancer. The duration of diagnosis delay was significant longer than that of treatment delay. Unlike rectal cancer, colon cancer was likely to be treated at an advanced stage with a short interval between symptom onset and treatment. Colon cancer patients with a history of biliary tract or gallbladder stones, aged ≥ 50 years and with abdominal mass or intestinal obstruction as the initial symptom were diagnosed and treated much earlier. In rectal cancer, women and non-smokers were diagnosed and treated quickly. Factors correlated with early cancer stage were found in colon cancer, including bloody stool as the initial symptom (OR = 2.63, 95% CI 1.08-6.25, P = 0.034) and a history of appendectomy (OR = 4.00, 95% CI 1.15-14.29, P = 0.029).

CONCLUSIONS

The factors contributing to early cancer detection were identified but their clinical value is limited. Diagnosis by symptoms suggesting CRC needs to be improved and CRC screening should be vigorously promoted.

Earlier diagnosis and treatment of symptomatic bowel cancer: can it be achieved and how much will it improve survival?

AIM

To determine current delays in diagnosis and treatment of bowel cancer, when and why they occur, and what effect they have on survival.

METHOD

A detailed review of the literature based on the development of the GP referral guidelines in 2000.

RESULTS

There is no evidence of a reduction in the delay to diagnosis and treatment of bowel cancer over the last 60 years. There is no strong theoretical basis for a benefit from earlier diagnosis of symptomatic bowel cancer and this is consistent with observational studies.

CONCLUSION

Campaigns to earlier diagnose bowel cancer will not be successful unless new strategies are developed. There is substantial evidence that earlier diagnosis of symptomatic bowel cancer will not improve survival in the majority of patients. However as excessive delays still occur in some patients it is reasonable to continue to aim to diagnose and treat all bowel cancer within 6 months of the onset of symptoms with an overall median of 3-4 months.

Flexible sigmoidoscopy and whole colonic imaging in the diagnosis of cancer in patients with colorectal symptoms

BACKGROUND

The aim was to identify the patients with colorectal symptoms most likely to benefit from whole colonic imaging (WCI) to diagnose colorectal cancer and those for whom flexible sigmoidoscopy (FS) may be initially sufficient.

METHODS

This prospective observational study (16 years) included 16 433 newly referred patients with symptoms or signs of colorectal cancer.

RESULTS

Colorectal cancer was diagnosed in 946 patients (diagnostic yield 5.8 per cent), 815 (86.2 per cent) in the rectum or sigmoid (distal) and 131 (13.8 per cent) in the proximal colon. Some 15 829 patients (96.3 per cent) presented with symptoms alone (without iron deficiency anaemia or abdominal mass). Of 787 cancers in these patients, 750 (95.3 per cent) were distal. The prevalence of proximal cancer above and below the age of 60 years was 0.4 per cent (33 of 8249) and 0.1 per cent (four of 7580) respectively. Of 16 256 patients having FS, 5665 (34.8 per cent) had WCI. Of the other 10 591, five subsequently presented with proximal cancers. FS missed ten (1.3 per cent) of 796 cancers.

CONCLUSION

Patients with iron deficiency anaemia or a mass require WCI. However, in patients with symptoms alone, FS detects 95 per cent of cancers, and the diagnostic yield of WCI after FS is very low. Alternative management strategies need to be developed to avoid unnecessary investigations in this low-risk group.

Lack of association between diagnostic and therapeutic delay and stage of colorectal cancer

BACKGROUND

A recent review suggests that there is no association between diagnostic and therapeutic delays and survival in colorectal cancer patients. However, the effect of tumour stage on the relationship between delay and survival in CRC should be clarified. We review here the evidence on the relationship between diagnostic and therapeutic delays and stage in colorectal cancer.

METHODS

We conducted a systematic review of Medline, Embase, Cancerlit and the Cochrane Database of Systematic Reviews to identify publications published between 1965 and 2006 dealing with delay, stage and colorectal cancer. A meta-analysis was performed based on the estimation of the odds ratios (OR) and on a random effects model.

RESULTS

We identified 50 studies, representing 18,649 patients. Thirty studies were excluded due to excessively restricted samples (e.g. exclusion of patients with intestinal obstruction or who died 1-3 months after surgery) or because they studied only a portion of the delay. Of the 37 remaining studies, great variability was noted in connection with the type of classification used for disease stage and the type of measurement used for the delay. Meta-analysis was performed based on 17 studies that included 5209 patients. The combined OR was 0.98 (95% confidence interval (CI): 0.76-1.25), suggesting a lack of association between delay and disease stage. In four studies, cancers of the colon and rectum were dealt with separately, and a meta-analysis was performed using the data for colon cancer (1001 patients) and for rectal cancer (799 patients). In both cases, the combined ORs overlapped 1.0, and showed opposite associations when studied separately: 0.86 (95% CI: 0.63-1.19) for the colon (i.e. more delay is associated with the earlier stage at diagnosis) and 1.93 (95% CI: 0.89-4.219) for the rectum (i.e. less delay is associated with the earlier stage).

CONCLUSIONS

When colorectal cancers are taken as a whole, there appears to be no association between diagnostic delay and disease stage when diagnosis is made. However, when cancers of the colon and the rectum are studied separately, there may be an opposite association. More studies about this issue are needed with larger and unrestricted samples.

Prevalence of pain in patients with cancer: a systematic review of the past 40 years

BACKGROUND

Despite the abundant literature on this topic, accurate prevalence estimates of pain in cancer patients are not available. We investigated the prevalence of pain in cancer patients according to the different disease stages and types of cancer.

PATIENTS AND METHODS

A systematic review of the literature was conducted. An instrument especially designed for judging prevalence studies on their methodological quality was used. Methodologically acceptable articles were used in the meta-analyses.

RESULTS

Fifty-two studies were used in the meta-analysis. Pooled prevalence rates of pain were calculated for four subgroups: (i) studies including patients after curative treatment, 33% [95% confidence interval (CI) 21% to 46%]; (ii) studies including patients under anticancer treatment: 59% (CI 44% to 73%); (iii) studies including patients characterised as advanced/metastatic/terminal disease, 64% (CI 58% to 69%) and (iii) studies including patients at all disease stages, 53% (CI 43% to 63%). Of the patients with pain more than one-third graded their pain as moderate or severe. Pooled prevalence of pain was >50% in all cancer types with the highest prevalence in head/neck cancer patients (70%; 95% CI 51% to 88%).

CONCLUSION

Despite the clear World Health Organisation recommendations, cancer pain still is a major problem.

Proximal shift of colorectal cancer in the Australian Capital Territory over 20 years

BACKGROUND

Several studies in other countries have demonstrated a change in subsite distribution of colorectal cancer, with increasing proximal cancers. Confirmation of such a change in Australia would have implications for screening and diagnosis of colorectal cancer.

AIMS

To determine whether there has been an increase in the proportion of proximal colorectal cancers in Australia, and whether there have been changes in other clinical and pathological aspects of colorectal cancer.

METHODS

A study of the hospital files of patients with colorectal cancer diagnosed and treated at all hospitals in the Australian Capital Territory (ACT) between 1989 and 1995 was compared with data from a published study of patients diagnosed between 1969 and 1976.

RESULTS

There was a proximal shift of cancers with a significant increase in the proportion of tumours in the hepatic flexure, ascending colon and caecum, more marked for females than males. There was a corresponding reduction in distal colorectal cancers. Time from onset of symptoms to diagnosis decreased, risk factors for colorectal cancer were noted more frequently, and endoscopy replaced barium enema X-ray as the main diagnostic modality. The resectability of cancers increased, stay in hospital and 30 day mortality declined. Despite apparent earlier presentation and improved surgical resectability, the proportion of patients with localised disease (Dukes' stage A and B) had not changed significantly.

CONCLUSIONS

We have detected a number of changes in clinical and pathological aspects of colorectal cancer over a 20 year period in the ACT, including a proximal shift in the subsite distribution of colorectal cancer. These changes suggest that proximal and distal colorectal cancers may have a different aetio-pathogenesis, and have implications for the investigation of patients with suspected colorectal cancer and in screening high-risk groups.

Emergency admission for surgery predicts disease progression during adjuvant 5-Fluouracil (5-FU)-based chemotherapy

OBJECTIVE

To determine the prognostic significance of a number of variables in patients that receive adjuvant chemotherapy for colorectal cancer.

PATIENTS AND METHODS

We reviewed the Cancer Centre records of 194 patients who received adjuvant chemotherapy following potentially curative resection of Dukes' B or C colorectal cancer. Eight variables were examined to determine which factor(s) predicted disease progression during the 6-month chemotherapy period.

RESULTS

Admission for emergency resection (due to bowel obstruction or perforation) rather than elective resection, and a poorly differentiated tumour rather than moderately/well differentiated were independent significant factors in predicting disease progression (P < 0.001 and P=0.011, respectively). However, sex, age, Dukes' stage, number of involved lymph nodes, delays in starting chemotherapy and compliance with chemotherapy regime had no significant effect on 6-month tumour progression.

CONCLUSION

These preliminary findings confirm data which suggest that emergency admission patients may suffer from intrinsically more aggressive disease than the average population with colorectal cancer.

How does colorectal cancer present? Symptoms, duration, and clues to location

OBJECTIVE

Most colorectal cancers still present with symptoms because screening, although effective, is not yet widely practiced. A careful history and physical examination are still the usual methods for suspecting colorectal cancer and ordering appropriate investigation. Therefore, we studied the symptoms, duration, and clues to location of colorectal cancer.

METHODS

We reviewed both hospital and office records for 204 consecutive patients with colorectal cancer, first diagnosed after symptoms, at one regional referral center from 1983-87. We abstracted data on demographic characteristics, presence and duration of 15 symptoms, and characteristics of the tumors.

RESULTS

The 194 patients included in the study were similar to those with colorectal cancer described elsewhere in terms of age, gender, and tumor location (58% distal to the splenic flexure), and stage (56% stage A or B). The most common symptoms were rectal bleeding (58%), abdominal pain (52%), and change in bowel habits (51%); the majority had anemia (57%) and occult bleeding (77%). The median duration of symptoms (from onset to diagnosis) was 14 wk (interquartile range 5-43). We found no association between overall duration of symptoms and the stage of the tumor. Patient age, gender, and proximal cancer location were also not associated with a longer duration of symptoms before diagnosis. We developed a rule for predicting a distal location of cancer using multiple logistic regression. Independent predictors were (odds ratio [95% CI]): Hb (1.34 for each g/dl [1.16-1.54]); rectal bleeding (3.45 [1.71-6.95]); constipation (3.16 [1.38-7.24]); and proximal symptoms (at least one of anorexia, nausea, vomiting, abdominal pain, or fatigue) (0.48 [0.20-1.02]). The rule had sensitivity of 93% and a specificity of 47%, with an area under the ROC curve of 0.79.

CONCLUSIONS

Until prevention of colorectal cancer is more common, we must continue to rely on clinical findings for detecting this cancer. Our results will remind physicians to keep colorectal cancer on the differential diagnosis of "chronic" gastrointestinal symptoms, and our decision rule may prompt earlier investigation with colonoscopy.

Do we believe what patients say about their neoplastic symptoms? An analysis of factors that influence the interviewer's judgement

In order to analyze factors that influence an interviewer's judgement of the validity of responses given by patients on the duration of their neoplastic signs and symptoms, 183 consecutive symptomatic patients hospitalized for a digestive tract neoplasm were personally interviewed. The validity of the answers was judged by the interviewers to be high in 156 cases (85%), and low in 27 (15%). The subjective validity of the interview (SVI) was inversely related to the time elapsed from first medical symptom to interview (TFMSI), even after adjusting for the duration of the interview (p < 0.05). SVI was not influenced by whether patient and interviewer agreed on the first symptom. SVI was inversely related to educational level (p < 0.01) and to occupational class (p = 0.04). Patients whose Karnofsky's Index (KI) was > or = 80 were over twice as likely to yield valid responses (TFMSI-adjusted odds ratio [OR] = 2.82, p = 0.037). Multivariate analyses selected education, TFMSI and KI as independent predictors of the interviewer assessment. The SVI of patients admitted to the hospital through the Emergency Department was lower than that of subjects whose admission was planned (OR = 6.49, p = 0.005). In this study SVI related in a logical manner to the characteristics of the interview, of the subjects and of their clinical course. It hence appeared to reasonably estimate the validity of data collected. Identifying factors that affect the reliability of patients' responses would help increase the validity of studies on the duration of cancer symptoms.

Cancer survival and the duration of symptoms. An analysis of possible forms of the risk function. ISDS II Project Investigators

The time interval between onset of symptoms and the diagnosis of cancer [symptom to diagnosis interval (SDI), or duration of symptoms] is a highly complex variable reflecting patient behaviour, the clinical course, the functioning of the health system and tumour biology. In order to assess possible forms of the risk function of SDI upon cancer survival whilst taking into account the effects of age, sex, tumour site and stage at diagnosis, 1887 symptomatic cases of lung, breast, stomach, colon, rectal, bladder cancer and lymphomas registered in the Tumour Registry of the Hospital del Mar (Barcelona) were analysed by means of survival curves and Cox proportional hazards regression. Subjects (mean age 64 years) were followed for a median length of 15 months after diagnosis (follow-up rate 93.5%). SDI showed a weak relationship with tumour stage at diagnosis and with survival: out of the seven sites studied, only in breast cancer was tumour extension at diagnosis significantly influenced by duration of symptoms, and only lung and rectal cancers showed a detectable form of the risk function of SDI upon survival; neither was linear, and for rectal cancer the relationship was complexly related with tumour stage. Hence, results show that forms of the risk function of duration of symptoms on cancer survival are specific to tumour sites, and that the interval should not be represented as a linear, continuous term. Studies analysing more complex sets of factors, processes and forms of the SDI function are needed.

Influence of "diagnostic delay" upon cancer survival: an analysis of five tumour sites

STUDY OBJECTIVE

The aim was to assess the relationship between survival, tumour stage, and the interval from first symptom to diagnosis (SDI, or duration of symptoms).

DESIGN

This was a retrospective follow up study of a cohort of patients registered in the tumour registry of the Hospital del Mar (Barcelona).

SETTING

Hospital based tumour registry, with patients derived mainly from the City of Barcelona.

PARTICIPANTS

1247 cases of lung, breast, stomach, colon, or rectal cancer were analysed using survival curves and Cox proportional hazards regression. Subjects (mean age 63.6 years) were followed for a median length of 12.9 months after diagnosis. At the time of diagnosis one fourth of patients had disseminated disease.

MEASUREMENTS AND MAIN RESULTS

Based on clinical records, a physician registered the onset time of the first symptom attributable to cancer (from which the SDI is computed), as well as the tumour stage at diagnosis. Other measurements followed standard tumour registry procedures. Overall, the crude mean SDI was 5.15 months (SD 8.03, median 2.03); only 24.5% of cases had an SDI less than a month. Crude mean SDIs by anatomical site were as follows: lung cancer 3.07 months; breast 7.44; stomach 5.34; colon 5.74; rectum 5.03. Tumour extension did not appear to be significantly influenced by SDI, only breast cancer showing a distinct pattern of increased extension with increasing SDI. As expected, the probability of survival decreased monotonically with increasing stage in all sites. Tumour site was also a significant predictor of survival, which at one year ranged from 93% for breast cancer to 28% for lung cancer. However, a longer SDI tended sometimes to be associated with a better chance of survival, a fact that was most apparent in colon cancer. All Cox proportional hazards models showed a consistent picture: SDI was not a significant predictor of survival (age and sex adjusted hazard ratios ranging from 0.97 to 1.01), neither was sex; age did predict survival, and so did site and stage.

CONCLUSIONS

The results provide further evidence of a very weak relationship between SDI and tumour stage at diagnosis (except for breast cancer), and between SDI and survival, thus emphasising some limitations within which early clinical detection operates. They also suggest that in addition to reflecting patient and physician behaviour, as well as the functioning of the health system, SDI may be influenced by the biological behaviour of the tumour.

The pros and cons of fecal occult blood testing for colorectal neoplasms

Testing feces for occult blood is widely recommended as a means of detecting subclinical colorectal tumors. Guaiac tests such as Hemoccult are the most widely used, but chemical sensitivity is relatively low and the tests are affected by dietary peroxidases, the state of fecal hydration, and certain drugs. The newly devised HemoQuant and immunologic techniques appear more sensitive and specific, but they require further evaluation before widespread clinical usage can be recommended. Occult blood screening has both merits and weaknesses. Testing does uncover subclinical colorectal cancer, often at a relatively early stage, but whether this actually improves the prognosis remains to be proven. Benign neoplastic polyps are also detected, although it is debatable whether this is a valid rationale for screening. Test sensitivity for malignancy varies from good to moderate, but is poor for benign polyps. Specificity is usually around 97%-98%, yet the predictive value of a positive test for cancer is only about 10%; hence most test-positive individuals are needlessly subjected to invasive colonic investigations. Reported figures on public compliance with occult blood testing vary widely from excellent to poor. Published costs of screening are usually quite low, but these overlook important indirect and hidden expenses and are therefore misleading. On balance, the problems of occult blood testing currently appear to outweight the merits. This could change, however, with the newer testing techniques and with awaited mortality data from controlled clinical trials now underway.

The workup of the asymptomatic patient with a positive fecal occult blood test

Twenty-two protocols for working up an asymptomatic patient who has a positive fecal occult blood test were evaluated using existing information on the prevalences of cancers, adenomas and other conditions in such patients; the natural history of colorectal cancer; the effectiveness of screening tests; risks; and costs. The authors estimate the impacts of the 22 workup strategies on outcomes such as the chance of finding an existing cancer or adenoma, risks (bleeding and perforation), and financial costs of different strategies involving rigid sigmoidoscopy, flexible sigmoidoscopy, barium enema, and colonoscopy. Two protocols were particularly effective. The first involves performing a barium enema study and following it with colonoscopy; if colonoscopy is negative, the barium enema study should be repeated. The second is to perform colonoscopy and if it is negative, follow it with a barium enema study.

Colorectal cancer: incidence, delay in diagnosis and stage of disease

In a study of 445 patients with colorectal cancer referred to our center during a 3-yr period, we investigated the following parameters and their interrelationships: sex, marital status, ethnic origin, place of residence, stage of disease, delay in diagnosis and factors responsible for delay. Localized disease was found in 52% of the patients, regional disease in 29% and metastatic disease in 19%. The incidence of colorectal cancer was significantly higher in Jews of European (occidental) descent than in Jews of Asian or North African (oriental) descent or in Arabs. The median and mean ages were significantly higher in the occidental than in the oriental Jewish group and significantly lower in the Arabs than in the oriental Jews. Diagnosis was delayed for more than 6 weeks in 52% of the patients. Responsibility for the delay could be attributed to the patient in 54% of these cases and to the physician in 47%. Administrative factors were responsible for the delay in 26%. (In 27% of the above delayers there was more than one agent responsible for the delay.) On average, patients in whom diagnosis was delayed had more advanced disease than those without delay. Also, patients with advanced disease had a longer delay on average than those with localized disease. The stage of disease at diagnosis was more advanced in the oriental than in the occidental Jews. No correlations were found between delay in diagnosis and either age or sex. There were more widowers with delay (21%) than with no delay (16%). In patients living outside Haifa delay was more prolonged than in those residing in the city. Educational programs aimed at the population at risk of developing neoplasm and especially at those likely to undergo delay in diagnosis are recommended. Postgraduate courses should be designed to instruct physicians on how to minimize delay in diagnosis.

Relationship of survival to stage of the tumour and duration of symptoms in colorectal cancer

It has been suggested that reduction of diagnostic delay in symptomatic colorectal cancer will not improve survival. Published reports show varying effects of duration of symptoms both on stage of cancer and on survival. However, tumour stage can be measured only at the end of the symptomatic period and, therefore, conclusions cannot be drawn about early diagnosis of symptomatic colorectal cancer and its effect on survival. On current evidence, early diagnosis and treatment may improve survival and should be encouraged.

Large bowel segment lengths and the distribution of colorectal cancer

Data was obtained on the average length and variability of each anatomical segment and for the whole of the large bowel from 50 patients examined by air contrast barium enema X-ray examination. Results were validated by measurements of the colon and rectum removed at autopsy in ten patients. Large bowel segment measurements from barium enema X-ray examinations were shown to be a valid basis for determining the average in vivo lengths of segments. The use of descriptive terms based on the anatomical location of colorectal carcinoma should be replaced by a more exact method of defining site distribution when recording and reporting the distribution of carcinomas and operative series and for teaching purposes.

Knowledge of colorectal cancer and attitude to occult blood testing among recent medical graduates in New South Wales

The extent to which new information on colorectal cancer (C.C.) is being transmitted to medical undergraduates was assessed in a repeated survey of new interns' knowledge of and attitudes on C.C. A probability sample of 214 graduates of the two Sydney medical schools was drawn as they commenced their internships in 1978. A comparable sample of 186 was drawn in 1980. Interns in each sub-sample completed a questionnaire of 54 pre-coded items of knowledge of C.C. epidemiology, early diagnosis, and followup, and on their attitudes towards C.C. On most topics knowledge was not well developed, and 1980 graduates were not significantly better informed than those of 1978. Almost three-quarters of 1980 interns intend using faecal occult blood testing.