Prioritisation of colonoscopy services in colorectal cancer screening programmes to minimise impact of COVID-19 pandemic on predicted cancer burden: A comparative modelling study

Objectives

Colorectal cancer (CRC) screening with a faecal immunochemical test (FIT) has been disrupted in many countries during the COVID-19 pandemic. Performing catch-up of missed screens while maintaining regular screening services requires additional colonoscopy capacity that may not be available. This study aimed to compare strategies that clear the screening backlog using limited colonoscopy resources.

Methods

A range of strategies were simulated using four country-specific CRC natural-history models: Adenoma and Serrated pathway to Colorectal CAncer (ASCCA) and MIcrosimulation SCreening ANalysis for CRC (MISCAN-Colon) (both in the Netherlands), Policy1-Bowel (Australia) and OncoSim (Canada). Strategies assumed a 3-month screening disruption with varying recovery period lengths (6, 12, and 24 months) and varying FIT thresholds for diagnostic colonoscopy. Increasing the FIT threshold reduces the number of referrals to diagnostic colonoscopy. Outcomes for each strategy were colonoscopy demand and excess CRC-related deaths due to the disruption.

Results

Performing catch-up using the regular FIT threshold in 6, 12 and 24 months could prevent most excess CRC-related deaths, but required 50%, 25% and 12.5% additional colonoscopy demand, respectively. Without exceeding usual colonoscopy demand, up to 60% of excess CRC-related deaths can be prevented by increasing the FIT threshold for 12 or 24 months. Large increases in FIT threshold could lead to additional deaths rather than preventing them.

Conclusions

Clearing the screening backlog in 24 months could avert most excess CRC-related deaths due to a 3-month disruption but would require a small increase in colonoscopy demand. Increasing the FIT threshold slightly over 24 months could ease the pressure on colonoscopy resources.

TERC polymorphisms are associated both with susceptibility to colorectal cancer and with longer telomeres

BACKGROUND AND AIMS

Shorter telomeres have been associated with increased risk of malignancy, including colorectal cancer (CRC). Telomere length is heritable and may be an intermediate phenotype linked to genetic susceptibility to CRC.

METHODS

In a large sample, the study investigated whether candidate single nucleotide polymorphisms (SNP) in 'telomere biology' genes were associated with telomere length in leucocytes. SNP associated with an increased risk of CRC were searched for separately.

RESULTS

Carriers of the common allele at SNP rs10936599, near the telomerase RNA component (TERC) locus, had significantly longer telomeres. It was independently found that the same rs10936599 allele was associated with increased risk of both CRC and colorectal adenomas. Neither telomere length nor CRC risk was associated with variation near telomerase reverse transcriptase or other telomere biology genes. In silico analysis showed that SNP rs2293607 was strongly correlated with rs10936599, mapped within TERC transcripts, had a predicted effect on messenger RNA folding and lay at a reported transcription factor binding site. TERC mRNA were expressed, differing only at the alleles of rs2293607, in CRC cell line HCT116. The long-telomere/CRC-risk allele was associated with higher levels of TERC mRNA and the formation of longer telomeres.

CONCLUSIONS

Common genetic variation at TERC is associated with both longer telomeres and an increased risk of CRC, a potential mechanism being reduced levels of cell senescence or death. This finding is somewhat paradoxical, given retrospective studies reporting that CRC cases have shorter telomeres than controls. One possibility is that that association actually results from poorer survival in patients with longer telomeres.

Comparative molecular pathology of sporadic hyperplastic polyps and neoplastic lesions from the same individual

AIM

The biology of colorectal hyperplastic polyps is of considerable relevance, because recent evidence suggests that under certain circumstances hyperplastic polyps may be precursors of neoplasms. The aim of this study was to assess and compare the clinical and molecular characteristics of hyperplastic polyps and neoplastic lesions removed from patients without the hyperplastic polyposis syndrome.

METHODS

One hundred and twenty six patients were identified through a series of genetic epidemiological studies. Each patient had at least one neoplastic lesion and one hyperplastic polyp; there was a total of 147 hyperplastic polyps. All lesions were evaluated for K-ras mutations, loss of heterozygosity (LOH) of the adenomatous polyposis coli (APC) gene, and microsatellite instability.

RESULTS

K-ras mutation was detected in 15 (10%) hyperplastic polyps, all from the rectosigmoid colon. No hyperplastic polyp had APC LOH or microsatellite instability. Patients with adenomas or carcinomas showing K-ras mutations were not more likely to have hyperplastic polyps with K-ras mutations. The average number of adenomas did not differ between those patients with hyperplastic polyps with K-ras mutations and those without K-ras mutations. There was no association between the hyperplastic polyp and the adenoma regarding the colon segments from which the two lesions were removed.

CONCLUSIONS

The sporadic hyperplastic polyp is a lesion with limited molecular change and no relation to patients' neoplastic lesions.

Cigarette smoking patterns in patients after treatment of bladder cancer

BACKGROUND

Assessment of smoking status and identification of those most likely to continue smoking are important in the management of patients who have bladder cancer, because continued smoking following diagnosis and treatment increases the likelihood of treatment-related complications, recurrence, second primary malignancies, and morbidity and mortality.

METHODS

Patients (n = 224) receiving follow-up care of previously treated bladder cancers completed a brief written survey assessing their post-diagnosis smoking patterns.

RESULTS

Despite the risks of continued smoking, 69% of the patients who had been active smokers at the time of diagnosis (n = 84) reported smoking at some point following the diagnosis and 45% reported smoking at the time of assessment. Patients diagnosed at earlier stages were more likely to continue smoking. Patients diagnosed at later stages were 2.80 times more likely to be continuous abstainers than those diagnosed sooner (95% CI, 1.08-7.25).

CONCLUSIONS

The findings underscore the need to assess smoking status and provide smoking-cessation advice and counseling within routine comprehensive care of bladder cancer patients.

Transitional cell cancer of the urinary tract and renal cell cancer in relation to acetaminophen use (United States)

Experimental and epidemiologic evidence have suggested that phenacetin use increases the risk of transitional cell cancers of the urinary tract. The drug is no longer marketed but a commonly used metabolite, acetaminophen, has been linked recently to an increased risk of renal cancer. We assessed the relation of acetaminophen use to the risk of transitional cell cancer of the urinary tract and of renal cell cancer with data from a hospital-based study of cancers and medication use conducted from 1976-96 in the eastern United States. We compared 498 cases of transitional cell cancer and 383 cases of renal cell cancer with 8,149 noncancer controls and 6,499 cancer controls and controlled confounding factors with logistic regression. For transitional cell cancer, the relative risk (RR) estimate for regular acetaminophen use that had begun at least a year before admission was 1.1 (95 percent confidence interval [CI] = 0.6-1.9) based on noncancer controls, and 0.9 (CI = 0.5-1.6) based on cancer controls. RR estimates for use that lasted at least five years, and for nonregular use, were also close to 1.0. For renal cell cancer, the corresponding estimates were again close to 1.0. Our results suggest that acetaminophen, as used in present study population, does not influence the risk of transitional cell cancer of the urinary tract or of renal cell cancer.

Induced and spontaneous abortion in relation to risk of breast cancer (United States)

The relation of induced and spontaneous abortion to the risk of breast cancer is evaluated in a hospital-based case-control interview study conducted in three cities in the United States from 1985 through 1995. Cases were 1,803 women aged 25 to 64 years with newly diagnosed invasive breast cancer; controls were 4,182 women of the same ages admitted for conditions unrelated to reproductive factors. Other breast cancer risk-factors were controlled through multiple logistic regression. The reference for all analyses was women who had never had an abortion, either induced or spontaneous. Among parous women, the relative risk (RR) estimate was 1.1 (95 percent confidence interval [CI] = 0.9-1.5) for induced abortion overall, 1.0 (CI = 0.7-1.4) for abortion before the first birth, and 1.3 (CI = 1.0-1.8) for abortion after at least one birth. Among nulliparous women, the relative risk estimate for induced abortion was 1.3 (CI = 0.9-1.9). There was no trend of increased risk with number of abortions, nor was there consistent evidence of an increased risk in any particular subgroup. Spontaneous abortion was not associated with increased risk of breast cancer, either among nulliparous women or among parous women. These findings provide little support for the hypothesis that induced abortion increases breast cancer risk overall or in particular subgroups.

Oral contraceptive use and breast cancer risk among African-American women

Recent epidemiologic studies, most of them in predominantly White populations, have suggested that long duration of oral contraceptive (OC) use may increase the risk of breast cancer at young ages. We assessed the relationship of OC use to the risk of breast cancer in African-American women aged 25 to 59 years, using interview data from a multipurpose hospital-based case-control study. Five hundred and twenty-four cases hospitalized for invasive breast cancer were compared with 1,021 controls with nonmalignant conditions unrelated to OC use. Relative risks (RR) and 95 percent confidence intervals (CI) were estimated relative to a reference category of use for less than 12 months; potential confounders were controlled by multiple logistic regression analysis. Among women under age 45, three or more years of OC use was associated with an increased risk of breast cancer: the RR estimate was 2.8 (CI = 1.5-5.0) for three to four years of use, and declined to 1.5 (CI = 08.3.0) for 10 or more years of use. Recency and timing of use did not explain the observed association. Among women aged 45 to 59, OC use was associated with little or no increase in risk: the RR estimate for three or more years of use was 1.3 (CI = 0.7-2.4). The findings add to the evidence from studies of White women and a recent study of Black women which have suggested an increased risk of breast cancer at young ages for moderate or long duration use of OCs.

Precursors of colorectal carcinoma. Biopsy and biologic markers

The term biologic marker (biomarker) of colorectal cancer refers in this article to an early preclinical phenotypic characteristic that relates to the risk for developing this cancer. Putative biologic markers in the normal colorectal mucosa of patients at risk include abnormal cell proliferation as determined by kinetic studies, ornithine decarboxylase activity, and polyamine synthesis. Alterations of mucin synthesis have been studied using both histochemical stains and lectin-binding techniques. Blood group and related carbohydrate antigens also have been evaluated as potential biomarkers in the normal mucosa. Biopsy small (less than 5 mm) polyps encountered at endoscopy has become a standard practice. Although a small polyp found to be an adenoma has a low likelihood of harboring high-grade dysplasia or invasive carcinoma, it represents an indicator of risk for colorectal neoplasia. Hyperplastic polyps, however, even though they have certain epidemiologic associations with colorectal neoplasia, are controversial as putative biomarkers of clinical relevance. Current research supports a concept of a field defect of the colorectal mucosa at risk for neoplasia, which may be identified by phenotypic abnormalities of the normal mucosa and the development of small adenomas.

Predictors of smoking prevalence among New York Latino youth

BACKGROUND

We examined prevalence rates and risk factors for smoking among Latino adolescents, using a multiethnic sample of sixth- and seventh-grade students (n = 3129) in 47 New York City public and parochial schools.

METHODS

The students completed questionnaires; self-reported smoking data were collected by means of the "bogus pipeline" technique. The largest group of Latino students (43%) was Puerto Rican; 20% were of Dominican background, 7% were Colombian, and 7% were Ecuadorian. "Current smoking" was defined as smoking at least once per month.

RESULTS

A series of logistic regression analyses indicated that peer influence was the strongest predictor of smoking. Family influence was important as well.

CONCLUSIONS

The results are discussed in terms of their implications for prevention.

Determinants of late stage diagnosis of breast and cervical cancer: the impact of age, race, social class, and hospital type

Previous studies of the relationship between cancer stage, age, and race have not controlled for social class and health care setting. Logistic regression analyses, using information from the New York State Tumor Registry and area-level social class indicators, demonstrated that, in New York City, older Black, lower class women in public hospitals were 3.75 and 2.54 times more likely to have late stage breast or cervical cancer, respectively, than were younger White, high social class women in non-public hospitals.

Risk and surveillance of individuals with colorectal polyps. Who Collaborating Centre for the Prevention of Colorectal Cancer

Since colorectal adenomas are very probably the precursors of colorectal cancer, their detection and removal should result in a decrease in the incidence and mortality from colorectal cancer. Individuals who harbour an adenoma have a 30-50% probability of having additional adenomas at that time, and a 30% probability of having additional adenomas later. Adenomas are prevalent in countries where colorectal cancer is prevalent, about two-thirds of them being tubular and the rest tubulovillous or villous. The initial management of patients with an adenoma consists in searching by colonoscopy the entire colon and removing all additional polyps. Surgical resection is required wherever there is invasive cancer with adverse histological factors. Follow-up in most patients can be after 2-4 years, earlier follow-up being reserved for patients with numerous polyps or with a polyp that had been removed piecemeal. The results of ongoing trials should provide firm guidelines for follow-up and could also be used in mathematical modelling to examine alternative strategies and to help understand the evolving patterns of appearance of new polyps. Finally, a deeper understanding of the biology and inherited and acquired genetics will help identify individuals at risk for adenomas initially and at follow-up. Nutritional factors may also provide a basis for prevention of adenomas in high-risk countries. Many of these issues are being addressed in current research.

Second malignancies after childhood Hodgkin's disease. The Memorial Sloan-Kettering Cancer Center experience

A review of the Memorial Sloan-Kettering Cancer Center experience with second malignancies (SM) after childhood Hodgkin's Disease (HD) identified 17 SM in 320 patients who survived more than 1 year from, and were 15 years old or younger at the time of, HD diagnosis (1949 to 1983). Of 254 previously untreated patients, 12 SM were noticed as compared with 0.606 expected on the basis of rates in the general pediatric population (relative risk, 19.8; 95% confidence interval, 10.2 to 34.6). For patients who received multi-agent chemotherapy, the cumulative probability of developing acute nonlymphocytic leukemia (ANLL) or bone sarcoma was 6.2% and 5.5%, respectively, at 10 years from the initiation of therapy; the cumulative risk of all SM in this group reached 18.7% at 15 years. For patients who received radiation alone or with single-agent chemotherapy, the cumulative risk of SM rose from 0% at 10 years and 2% at 15 years, to 10.7% at 25 years from the initiation of treatment. The risk of ANLL after childhood HD was highest in the first 5 to 10 years after combined modality treatment, and aggressive forms of NHL were associated with excessive immunosuppression. Bone sarcomas predominated in solid SM in the first decade after HD treatment, whereas "adult-type" cancers, for example, breast and colon carcinomas, were more delayed. Our findings, supported by a literature review, point to a therapy-related enhanced risk of approximately age-appropriate solid SM. This possibility mandates careful surveillance of long-term survivors of childhood HD.

Geographically-based cancer control: methods for targeting and evaluating the impact of screening interventions on defined populations

Successful implementation of cancer control programs depends on efficient targeting to those at highest risk of developing and dying from the disease. This study presents a methodology for targeting cancer screening on the basis of population and disease variation among small geographic areas. Techniques for quantifying the impact of targeting on the predictive value of a positive test are demonstrated, using 329 New York City health areas. Age-truncated crude incidence, late-stage incidence and mortality rates for breast, cervix, and colorectal cancer are used, using site-specific truncation points relevant to the age groups appropriate for screening. Coefficient alpha was used to determine rate stability with 2, 3, 5 and 7 years of data. The stability of most small area rates was found to reach acceptable levels only with 5 and 7 years of data. Targeting into areas where breast cancer prevalence was high increased the expected predictive value of a positive test by as much as 50% when compared with areas of average prevalence. Geographic targeting will be most useful where between-area variability in prevalence is large and within-area variability is small. The implications of these results are discussed and future studies are suggested.

Drug utilization review in an HMO. I. Introduction and examples of methodology

An experimental drug utilization review program was developed for a health maintenance organization (HMO). The objectives of the program were to develop and implement an ongoing mechanism for reviewing drug use using criteria based on the scientific literature, and to evaluate the effect of the drug use review program on physician precribing patterns. Seven therapeutic categories of drugs, accounting for over 65 per cent of prescribing, were selected and criteria developed for their use. The drug use review prcedure is described briefly. The evaluation of the drug use review program is based on a comparison of rates of prescription use for specific therapeutic categories before and after the criteria were ceveloped and approved. As an example, data for the antihistamine therapeutic category are presented. Criteria for prescribing antihistamines suggested restricting use of combination cold preparations and refraiming from antihistamine use in viral upper respiratory tract infections. After the criteria were adopted, prescribing of antihistamines for viral URIs declined, particularly in pediatrics. In general, prescribing of combination antihistamine preparations did not change; where one combination preparation was deleted from the formulary, prescribers appeared to substitute another combination preparation.