Analysis of survival versus patient and doctor delay of treatment in gastrointestinal cancer

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.

Cancer diagnostic tools to aid decision-making in primary care: mixed-methods systematic reviews and cost-effectiveness analysis

BACKGROUND

Tools based on diagnostic prediction models are available to help general practitioners diagnose cancer. It is unclear whether or not tools expedite diagnosis or affect patient quality of life and/or survival.

OBJECTIVES

The objectives were to evaluate the evidence on the validation, clinical effectiveness, cost-effectiveness, and availability and use of cancer diagnostic tools in primary care.

METHODS

Two systematic reviews were conducted to examine the clinical effectiveness (review 1) and the development, validation and accuracy (review 2) of diagnostic prediction models for aiding general practitioners in cancer diagnosis. Bibliographic searches were conducted on MEDLINE, MEDLINE In-Process, EMBASE, Cochrane Library and Web of Science) in May 2017, with updated searches conducted in November 2018. A decision-analytic model explored the tools' clinical effectiveness and cost-effectiveness in colorectal cancer. The model compared patient outcomes and costs between strategies that included the use of the tools and those that did not, using the NHS perspective. We surveyed 4600 general practitioners in randomly selected UK practices to determine the proportions of general practices and general practitioners with access to, and using, cancer decision support tools. Association between access to these tools and practice-level cancer diagnostic indicators was explored.

RESULTS

Systematic review 1 - five studies, of different design and quality, reporting on three diagnostic tools, were included. We found no evidence that using the tools was associated with better outcomes. Systematic review 2 - 43 studies were included, reporting on prediction models, in various stages of development, for 14 cancer sites (including multiple cancers). Most studies relate to QCancer^® (ClinRisk Ltd, Leeds, UK) and risk assessment tools.

DECISION MODEL

In the absence of studies reporting their clinical outcomes, QCancer and risk assessment tools were evaluated against faecal immunochemical testing. A linked data approach was used, which translates diagnostic accuracy into time to diagnosis and treatment, and stage at diagnosis. Given the current lack of evidence, the model showed that the cost-effectiveness of diagnostic tools in colorectal cancer relies on demonstrating patient survival benefits. Sensitivity of faecal immunochemical testing and specificity of QCancer and risk assessment tools in a low-risk population were the key uncertain parameters.

SURVEY

Practitioner- and practice-level response rates were 10.3% (476/4600) and 23.3% (227/975), respectively. Cancer decision support tools were available in 83 out of 227 practices (36.6%, 95% confidence interval 30.3% to 43.1%), and were likely to be used in 38 out of 227 practices (16.7%, 95% confidence interval 12.1% to 22.2%). The mean 2-week-wait referral rate did not differ between practices that do and practices that do not have access to QCancer or risk assessment tools (mean difference of 1.8 referrals per 100,000 referrals, 95% confidence interval -6.7 to 10.3 referrals per 100,000 referrals).

LIMITATIONS

There is little good-quality evidence on the clinical effectiveness and cost-effectiveness of diagnostic tools. Many diagnostic prediction models are limited by a lack of external validation. There are limited data on current UK practice and clinical outcomes of diagnostic strategies, and there is no evidence on the quality-of-life outcomes of diagnostic results. The survey was limited by low response rates.

CONCLUSION

The evidence base on the tools is limited. Research on how general practitioners interact with the tools may help to identify barriers to implementation and uptake, and the potential for clinical effectiveness.

FUTURE WORK

Continued model validation is recommended, especially for risk assessment tools. Assessment of the tools' impact on time to diagnosis and treatment, stage at diagnosis, and health outcomes is also recommended, as is further work to understand how tools are used in general practitioner consultations.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42017068373 and CRD42017068375.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology programme and will be published in full in Health Technology Assessment; Vol. 24, No. 66. See the NIHR Journals Library website for further project information.

Is increased time to diagnosis and treatment in symptomatic cancer associated with poorer outcomes? Systematic review

BACKGROUND

It is unclear whether more timely cancer diagnosis brings favourable outcomes, with much of the previous evidence, in some cancers, being equivocal. We set out to determine whether there is an association between time to diagnosis, treatment and clinical outcomes, across all cancers for symptomatic presentations.

METHODS

Systematic review of the literature and narrative synthesis.

RESULTS

We included 177 articles reporting 209 studies. These studies varied in study design, the time intervals assessed and the outcomes reported. Study quality was variable, with a small number of higher-quality studies. Heterogeneity precluded definitive findings. The cancers with more reports of an association between shorter times to diagnosis and more favourable outcomes were breast, colorectal, head and neck, testicular and melanoma.

CONCLUSIONS

This is the first review encompassing many cancer types, and we have demonstrated those cancers in which more evidence of an association between shorter times to diagnosis and more favourable outcomes exists, and where it is lacking. We believe that it is reasonable to assume that efforts to expedite the diagnosis of symptomatic cancer are likely to have benefits for patients in terms of improved survival, earlier-stage diagnosis and improved quality of life, although these benefits vary between cancers.

Relationship of diagnostic and therapeutic delay with survival in colorectal cancer: a review

BACKGROUND

Early diagnosis of colorectal cancer before the onset of symptoms improves survival. Once symptoms have occurred, however, the effect of delay on survival is unclear. We review here evidence on the relationship of diagnostic and therapeutic delay with survival in colorectal cancer.

METHODS

We conducted a systematic of Medline, Embase, Cancerlit and the Cochrane Database of Systematic Reviews to identify publications published between 1962 and 2006 dealing with delay, survival and colon cancer. A meta-analysis was performed based on the calculation of the relative risk (RR) and on a model of random effects.

RESULTS

We identified 40 studies, representing 20,440 patients. Fourteen studies were excluded due to excessively restricted samples (e.g. exclusion of patients with intestinal obstruction, with tumours at stage C or D at the time of diagnosis, or who died 1-3 months after surgery); or because they studied only a portion of the delay. Of the 26 remaining studies, 20 showed no association between delay and survival. In contrast, four studies showed that delay was a factor contributing to better prognosis, and two showed that it contributed to poorer prognosis. There was no association between delay and survival when the colon and rectum were considered separately, when a multivariate analysis was performed, and when the effects of tumour stage and degree of differentiation were taken into account. To perform a meta-analysis, 18 additional studies were excluded, since the published articles did not specify the absolute numbers. In the remaining eight studies, the combined relative risk (RR) of delay was 0.92 (confidence interval (CI) 95%: 0.87-0.97).

CONCLUSIONS

The results of the review suggest that there is no association between diagnostic and therapeutic delay and survival in colorectal cancer patients. Colon and rectum should be assessed separately, and it is necessary to adjust for other relevant variables such as tumour stage.

Relationship between delayed diagnosis and the degree of invasion and survival in lung cancer

BACKGROUND AND OBJECTIVES

The aim of this study is to evaluate the relationship between the interval from first symptom to diagnosis (SDI) and the degree of invasion and survival in lung cancer.

METHODS

Three hundred seventy-eight patients with lung cancer were included. SDI was defined as the time calculated from the cytohistologic confirmation of the diagnosis of cancer and the first symptoms noted by the patient and attributed to cancer by the physician. The degree of invasion was determined by TNM classification.

RESULTS

The median SDI was 2.1 months, and did not correlate with stage. Survival decreased progressively according to TNM classification. Adjusting for age, sex, SDI and TNM, survival was influenced by age (RR=1.02) and by staging [Stage (Ib) RR=1.3; stage (IIIa) RR=2.6; stage (IIIb) RR=4.06; stage (IV) RR=7.5]. SDI was not found to affect survival (RR=1.01; 95% CI: 0.94-1.08). In the small cell group, SDI also failed to modify survival.

CONCLUSIONS

The results of this study indicate that SDI has no effect on the stage or survival of patients with lung cancer.

Biological considerations with pelvic neoplasms

The strategy of therapy for any neoplasm is determined to a significant degree by the biological characteristics of the neoplasm. The ones benefited most by surgical ablation are the cancers that grow locally but never metastasize. The second group is composed of neoplasms with exceedingly slow growth rates permitting long periods of symptom-free survival before recidivation. Many such cancers occur in pelvic structures requiring understanding of the nature of the cancers and then techniques necessary for their resection. The review provides an introduction to some of the relevant biological considerations.

Duration of colorectal cancer symptoms and survival: the effect of confounding clinical and pathological variables

The relationship between symptom duration and long-term survival following colorectal cancer is complex, and a number of factors may influence the length of time from onset of symptoms of cancer diagnosis. We prospectively studied 777 consecutive colorectal cancer patients to determine the association between symptom duration and survival independent of other clinical and pathological features. We used survival curves, the logrank test and Cox's proportional hazards model to assess possible changes in relative risk of death with increasing symptom duration, without making any a priori assumptions. We found that symptom duration shortened with advanced tumour stage (P < 0.0006) and was also shorter for patients presenting with bowel obstruction (P < 0.0001). Univariate survival analysis showed that long-term survival increased consistently with symptom duration (P < 0.001). However, when the effect of tumour stage and bowel obstruction were accounted for in a multivariate analysis, no decrease in the relative risk of death was seen as symptom duration increased. The addition of other variables to the proportional hazards model such as age, sex or tumour site did not further influence the risk function form of symptom duration. Our results suggest that early diagnosis of colorectal cancer should remain our goal when assessing patients with suggestive gastrointestinal symptoms.

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.

Rates of growth of human solid neoplasms: Part I

The purpose of this article is to consolidate data collected from a variety of sources that have permitted calculations of the rates of growth of human neoplasms. These sources include Fischel State Cancer Hospital (Columbia, MO); Mallinckrodt Institute of Radiology, (St. Louis, MO); Roentgen Diagnostic Institute, Allmanna Sjukhuset (Malmo, Sweden); University of Louisville (Louisville, Kentucky); University of Heidelberg (Heidelberg, Germany); and St. Luke's Hospital (St. Louis, MO). Included in the data are laboratory measurements of cell replication rates. All gross measurements were made either on imaging studies or with a centimeter scale for surface or palpable neoplasms. Data have been reported for breast and pulmonary cancers and metastases of many types, melanomas, skeletal sarcomas, benign and malignant colonic neoplasms, and isolated cases of less frequent neoplasms. Related cytokinetic measurements by tritriated thymidine labelling, bromodeoxyuridine labelling, S-phase fraction from DNA flow cytometric analysis, and mitotic indices are discussed. The various mathematical formulae applicable to the analysis of the collected data and the determination of rates and patterns of growth are included. Also considered are the clinical implications of these data and the importance of ever better knowledge on the cytokinetics of human cancer. Prior studies on the evolution of insight into this field are cited and discussed. The authors conclude that a more accurate quantification of the growth rates of human cancer is essential for understanding the biological variance of human cancers seen clinically.

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.

Survival of colorectal cancer patients in relation to duration of symptoms and other prognostic factors

The effect of duration of symptoms and other prognostic factors on survival was studied by interview using a population-based sample of 154 colorectal cancer patients. The authors found that symptom durations of up to approximately one year before diagnosis had no effect on survival. In addition, it was found that the total number of symptoms was a statistically significant predictor of survival, although no single symptom had a significant effect. Stage, sex, and site also were found to be significant predictors of survival, whereas age, socioeconomic status, and other factors were not predictive.

Analysis of survival and recurrence vs. patient and doctor delay in treatment of breast cancer

Two hundred thirty-seven patients with cancer of the breast treated with radical mastectomy were reviewed. Coefficients of correlation between patient's and doctor's delay vs. survival were not significant at p smaller than 0.05. No significant relationship between delay and time of recurrence was found.