Distinct molecular features of colorectal cancer in Ghana

Advancing oncology drug therapies for sub-Saharan Africa

Cancer incidence is rising across sub-Saharan Africa (SSA), and is often characterized by late-stage presentation, early age of onset and poor survival. While a number of oncology drugs are now improving the length and quality of life for cancer patients in high-income countries, significant disparities in access to a range of oncology therapeutics exist for SSA. A number of challenges to drug access such as drug costs, lack of infrastructure and trained personnel must be urgently addressed to advance oncology therapies for SSA. We present a review of selected oncology drug therapies that are likely to benefit cancer patients with a focus on common malignancies in SSA. We collate available data from seminal clinical trials in high-income countries to highlight the potential for these therapeutics to improve cancer outcomes. In addition, we discuss the need to ensure access to drugs within the WHO Model List of Essential Medicines and highlight therapeutics that require consideration. Available and active oncology clinical trials in the region is tabulated, demonstrating the significant gaps in access to oncology drug trials across much of the region. We issue an urgent call to action to address drug access due to the predicted rise in cancer burden in the region in coming years.

Epidemiology and genetics of early onset colorectal cancer—African overview with a focus on Ethiopia

Colorectal cancer (CRC) is a common cause of cancer-related death worldwide, with high rates of late diagnosis and increased mortality in sub-Saharan Africa. Furthermore, there is an alarming uptrend in the incidence of early onset colorectal cancer (EOCRC) across the globe, thus necessitating the need for early screening in general and special populations. There is, however, limited data available on the incidence and genetic characteristics of EOCRC from resource-poor countries, particularly Africa. Moreover, there is lack of clarity if recommendations and mechanisms proposed based on data from resource-rich countries applies to other regions of the world. In this review, we appraise the literature on EOCRC, its overall incidence, and genetic components as it pertains to sub-Saharan Africa. In addition, we highlight epidemiologic and epigenetic findings of our EOCRC cohort in Ethiopia.

Morbidity and oncological outcomes after intersphincteric resection of the rectum for low-lying rectal cancer: experience of a single center in a lower-middle-income country

BACKGROUND

Intersphincteric resection (ISR) of the rectum for low-lying rectal cancer with colo-anal anastomosis was introduced years ago, allowing for bowel continuity, and avoiding permanent stomas. The colorectal unit of Korle Bu Teaching Hospital adopted this procedure in 2014 when indicated, for the management of rectal cancers, where hitherto, abdominoperineal resection of the rectum with a permanent stoma was indicated. This study aimed to assess morbidity, mortality, and oncological outcomes associated with ISR of the rectum and determine the factors contributing to these.

METHODS

This was an observational study from prospectively stored data. All patients who underwent intersphincteric resection of the rectum due to low-lying rectal cancer from July 2014 to June 2021 were included in the study, and their records were assessed for intra-operative and 30-day postoperative complications, as well as mortality and their related risk factors and their oncological outcomes in terms of local recurrence at one year.

RESULTS

102 patients were included in this analysis. Six percent (6/102) of patients had intra-operative complications, including bleeding, and 41% (42/102) had 30-day postoperative complications, which were associated with pelvic side wall attachment of tumor and intra-op complications. Mortality risk was 12.7% (13/102) in the early postoperative period, and nine patients had a local recurrence within the first year of surgery.

CONCLUSION

There is a high risk of early postoperative morbidity and mortality after intersphincteric resection of the rectum in our setting. The oncological outcomes are favorable in a population that abhors a permanent colostomy.

Genomic landscape of colorectal carcinoma in sub-Saharan Africa

Our understanding of the molecular classification of colorectal carcinoma (CRC) has evolved significantly over the past two decades. Tumours can be broadly categorised as microsatellite stable (MSS), microsatellite instability (MSI) or CpG island-methylator phenotype. Prognostic and predictive information is provided by these categories. The overwhelming majority of the data on which these categories are based have originated from Europe and North America. There is a dearth of information represented from Africa and indigenous African patients. However, some small studies and preliminary data have shown significant differences in all of these groups. The prevalence of MSI in Africa is consistently reported as almost double that of European and North American data. Interestingly, BRAF V600E mutations and MLH1 promotor hypermethylation seem to be uncommon in Africa. The high proportion of MSI tumours is only partly accounted for by germline mutations in mismatch repair genes (Lynch syndrome), suggesting that there are likely to be other mechanisms at play. Within the MSS group, preliminary data suggest that the typical molecular pathways (Wingless/Integrated pathway activation) may not be as dominant in Africa. The purpose of this review is to summarise the current state of the molecular genetic landscape of CRC in Africa and provide insights into areas for further study.

A GNAS Gene Mutation's Independent Expression in the Growth of Colorectal Cancer: A Systematic Review and Meta-Analysis

Globally, colorectal carcinoma CRC is the third most common cancer and the third most common reason for cancer-associated mortality in both genders. The GNAS mutations are significantly linked with poor prognosis and failed treatment outcomes in CRC. A systematic review and meta-analysis of multiple studies executed following Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) criteria and registered with PROSPERO (registration number: CRD42021256452). The initial search includes a total of 271 publications; however, only 30 studies that merit the eligibility criteria were eventually chosen. Data analysis via OpenMeta Analyst and comprehensive meta-analysis 3.0 (CMA 3.0) software were used to investigate the prevalence of GNAS gene mutation among CRC patients. The meta-analysis consisted of 10,689 participants with most being males 6068/10,689 (56.8%). Overall, prevalence of GNAS mutations was 4.8% (95% CI: 3.1−7.3) with I2 = 94.39% and (p < 0.001). In 11/30 studies, the frequency of GNAS gene mutations was majorly in codons R201C [40.7% (95% CI: 29.2−53.2%)] and in codon R201H [39.7% (95% CI = 27.1−53.8)]. Overall prevalence of GNAS mutations was highest among the male gender: 53.9% (95% CI: 48.2−59.5%: I2 = 94.00%, (p < 0.001), tumour location (colon): 50.5% (95% CI: 33.2−67.6%: I2 = 97.93%, (p < 0.001), tumour grade (Well): 57.5% (95% CI: 32.4−79.2%: I2 = 98.10%, (p < 0.001) and tumour late stage: 67.9% (95% CI: 49.7−84.3%: I2 = 98.%, (p < 0.001). When stratified according to study location, a higher prevalence was observed in Japan (26.8%) while Italy has the lowest (0.4%). Overall prevalence of GNAS gene mutations was 4.8% with codons R201C and R201H being the most mutated, and the results conformed with numerous published studies on GNAS mutation.

A Systematic Review and Meta-analysis on the Occurrence of Biomarker Mutation in Colorectal Cancer among the Asian Population

Globally, colorectal carcinoma (CRC) is the third most common cancer and the third major cause of cancer-related death in both sexes. KRAS and BRAF mutations are almost mutually exclusively involved in the pathogenesis of CRC. Both are major culprits in treatment failure and poor prognosis for CRC. Method. A systematic review and meta-analysis of various research was done following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. This trial is registered with PROSPERO CRD42021256452. The initial search included 646 articles; after the removal of noneligible studies, a total of 88 studies was finally selected. Data analysis was carried out using OpenMeta Analyst and Comprehensive Meta-Analysis 3.0 (CMA 3.0) software to investigate the prevalence of KRAS and BRAF mutations among patients with CRC in Asia. Results. The meta-analysis comprises of 25,525 sample sizes from Asia with most being male 15,743/25525 (61.7%). Overall prevalence of KRAS mutations was (59/88) 36.3% (95% CI: 34.5-38.2) with I² = 85.54% (P value < 0.001). In 43/59 studies, frequency of KRAS mutations was majorly in codon 12 (76.6% (95% CI: 74.2–78.0)) and less in codon 13 (21.0% (95% CI: 19.1-23.0)). Overall prevalence of BRAF mutations was 5.6% (95% CI: 3.9-8.0) with I² = 94.00% (P value < 0.001). When stratified according to location, a higher prevalence was observed in Indonesia (71.8%) while Pakistan has the lowest (13.5%). Conclusion. Total prevalence of KRAS and BRAF mutations in CRC was 36.6% and 5.6%, respectively, and the results conformed with several published studies on KRAS and BRAF mutations.

A Review of Cancer Genetics and Genomics Studies in Africa

Cancer is the second leading cause of death globally and is projected to overtake infectious disease as the leading cause of mortality in Africa within the next two decades. Cancer is a group of genomic diseases that presents with intra- and inter-population unique phenotypes, with Black populations having the burden of morbidity and mortality for most types. At large, the prevention and treatment of cancers have been propelled by the understanding of the genetic make-up of the disease of mostly non-African populations. By the same token, there is a wide knowledge gap in understanding the underlying genetic causes of, and genomic alterations associated with, cancer among black Africans. Accordingly, we performed a review of the literature to survey existing studies on cancer genetics/genomics and curated findings pertaining to publications across multiple cancer types conducted on African populations. We used PubMed MeSH terms to retrieve the relevant publications from 1990 to December 2019. The metadata of these publications were extracted using R text mining packages: RISmed and Pubmed.mineR. The data showed that only 0.329% of cancer publications globally were on Africa, and only 0.016% were on cancer genetics/genomics from Africa. Although the most prevalent cancers in Africa are cancers of the breast, cervix, uterus, and prostate, publications representing breast, colorectal, liver, and blood cancers were the most frequent in our review. The most frequently reported cancer genes were BRCA1, BRCA2, and TP53. Next, the genes reported in the reviewed publications’ abstracts were extracted and annotated into three gene ontology classes. Genes in the cellular component class were mostly associated with cell part and organelle part, while those in biological process and molecular function classes were mainly associated with cell process, biological regulation, and binding, and catalytic activity, respectively. Overall, this review highlights the paucity of research on cancer genomics on African populations, identified gaps, and discussed the need for concerted efforts to encourage more research on cancer genomics in Africa.

Comparison of universal screening in major lynch-associated tumors: a systematic review of literature

Lynch syndrome (LS) is associated with an increased lifetime risk of several cancers including colorectal (CRC), endometrial (EC), ovarian (OC), urinary (UT) and sebaceous tumors (ST). The benefit for universal screening in CRC and EC is well known. However, this benefit in other major lynch-associated tumors is unclear. We performed a systematic review of all published articles in the MEDLINE database between 2005 to 2017 to identify studies performing universal screening for LS in unselected CRC, EC, OC, UT and ST. All cases with MSI-H (instability in two or more markers) or missing one or more proteins on IHC testing were considered screening positive. Cases with MLH1 promoter hypermethylation or BRAF mutation positive were considered to have somatic mutations. A total of 3788 articles were identified in MEDLINE yielding 129 study arms from 113 studies. The overall pooled yield of universal LS screening and germline mismatch gene mutation was significantly different across the major LS-associated tumors (Mann Whitney test, p < 0.001). The pooled screening yield was highest in ST [52.5% (355/676), 95% CI 48.74-56.26%] followed by EC [22.65% (1142/5041), 95% CI 21.54-23.86%], CRC [11.9% (5649/47,545), 95% CI 11.61-12.19%], OC [11.29% (320/2833), 95% CI 10.13-12.47%] and UT [11.2% (31/276), 95% CI 7.48-14.92%]. ST also had the highest pooled germline positivity for mismatch repair gene mutation [18.8%, 33/176, 95%CI 13.03-24.57], followed by EC [2.6% (97/3765), 95% CI 2.09-3.11], CRC [1.8% (682/37,220), 95% CI 1.66-1.94%], UT [1.8%(3/164), 95% CI - 0.24-3.83%] and OC [0.83%(25/2983), 95% CI 0.48-1.12%]. LS screening in EC yielded significantly higher somatic mutations compared to CRC [pooled percentage 16.94% [(538/3176), 95%CI 15.60-18.20%] vs. 5.23% [(1639/26,152), 95% CI 4.93-5.47%], Mann Whitney test, p < 0.0001. Universal LS testing should be routinely performed in OC, UT and STs in addition to CRC and EC. Our findings also support consideration for IHC and somatic mutation testing before germline testing in EC due to higher prevalence of somatic mutations as well as germline testing in all patients with ST. Our results have implications for future design of LS screening programs and further studies are needed to assess the cost effectiveness and burden on genetic counselling services with expanded universal testing for LS.

Worldwide variation in lynch syndrome screening: case for universal screening in low colorectal cancer prevalence areas

To perform a systematic assessment of universal Lynch syndrome (LS) screening yield in colorectal cancer (CRC) patients around the world. Universal screening for LS is recommended in all CRC patients. However, the variation in yield of LS screening in the setting of significant global variation in CRC prevalence is unknown. A systematic review of articles in the MEDLINE database was performed to identify studies performing universal screening for LS. All cases with microsatellite instability (MSI-H) or missing one or more proteins on immunohistochemistry (IHC) were considered screening positive. The overall pooled yield of universal LS screening in 97 study arms from 89 identified studies was 11.9% (5649/47545) and the overall pooled percentage of confirmed LS patients was 1.8% (682/37220). LS screening positivity varied significantly based on geographic region (Kruskal Wallis test, p < 0.001) and reported 5-year CRC prevalence in the country (Fisher's exact, p < 0.001). Significant inverse correlation was found between LS screening positivity and 5-year CRC prevalence (Pearson correlation, r =  - 0.56, p < 0.001). The overall yield of LS screening was 15.00% (382/2553) and rate of confirmed LS was 7.7% (113/1475) in LS screening done in patients ≤ 50 years (16 studies). There is significant geographic variation in LS screening positivity with higher yield in countries with lower prevalence of CRC. Our results highlight the importance of universal LS screening in younger patients and low CRC prevalence countries.

Treatment of colorectal cancer in Sub-Saharan Africa: Results from a prospective Nigerian hospital registry

BACKGROUND

Colorectal cancer (CRC) is the third most common cancer worldwide. Mortality for CRC is improving in high income countries, but in low and middle income countries, rates of disease and death from disease are rising. In Sub-Saharan Africa, the ratio of CRC mortality to incidence is the highest in the world. This study investigated the nature of CRC treatment currently being offered and received in Nigeria.

METHODS

Between April 2013 and October 2017, a prospective study of consecutively diagnosed cases of CRC was conducted. Patient demographics, clinical features, and treatment recommended and received was recorded for each case. Patients were followed during the study period every 3 months or until death.

RESULTS

Three hundred patients were included in our analysis. Seventy-one percent of patients received a recommended surgical operation. Of those that didn't undergo surgery as recommended, 37% cited cost as the main reason, 30% declined due to personal reasons, and less than 5% absconded or were lost to follow up. Approximately half of patients (50.5%) received a chemotherapy regimen when it was recommended, and 4.1% received radiotherapy when this was advised as optimal treatment. With therapy, the median overall survival for patients diagnosed with stage III and stage IV CRC was 24 and 10.5 months respectively. Overall, we found significantly better median survival for patients that received the recommended treatment (25 vs 7 months; P < .01).

CONCLUSIONS

A number of patients were unable to receive the recommended treatment, reflecting some of the burden of untreated CRC in the region. Receiving the recommended treatment was associated with a significant difference in outcome. Improved healthcare financing, literacy, training, access, and a better understanding of tumor biology will be necessary to address this discrepancy.

Microsatellite instability in Costa Rican patients with colorectal adenocarcinoma and its association with overall survival and response to fluoropyrimidine-based chemotherapy

BACKGROUND

Microsatellite instability (MSI) is a prognostic and predictive factor in colorectal cancer (CRC). Previous trials have acknowledged that MSI prevalence varies according to ethnicity. The aim of this study was to determine the prevalence of MSI among CRC patients from Costa Rica and to analyze its influence on overall survival (OS) and response to fluoropyrimidine-based chemotherapy.

METHODS

We conducted a retrospective cohort study with all diagnosed CRC cases from 2010 to 2015 in a referral center in San José, Costa Rica. MSI was determined by immunohistochemical analysis. Clinical and epidemiological variables were retrieved from medical records. An univariate and multivariate COX regression analysis was performed to evaluate the association between MSI and mortality in the overall population and in those patients treated or not with fluoropyrimidine-based chemotherapy.

RESULTS

553 CRC patients were identified during the study timeframe, and 165 of them were diagnosed with MSI (29.84 %; 95 % Confidence Interval CI: 26.02-33.65%). MSI was associated with M1 disease, and right-sided tumor location. After adjusting for potential confounders, MSI was an independent prognostic factor for OS (Hazard Ratio (HR): 0.56; 95 %CI: 0.43-0.67; Log-rankp = 0.03). MSI status did not modify the response to fluoropyrimidine-based chemotherapy (HR: 0.56; 95 %CI: 0.18-1.80; Log-rank: p = 0.33).

CONCLUSIONS

MSI was detected in a higher proportion of CRC patients than previously reported for other non-Hispanic populations. MSI was an independent prognostic factor for OS, but did not predict the efficacy of cytotoxic treatment with Fluoropyrimidine-based chemotherapy.

Prevalence of BRAF gene mutation in samples of primary and metastatic colorectal cancer: A meta-analysis

INTRODUCTION

Understanding the prevalence and biology of BRAF gene can improve the treatment methods of cancerous patients. This study aims to estimate the prevalence of BRAF gene mutation in samples of primary and metastatic colorectal cancer using meta-analysis method.

METHODS

We searched PubMed, Scopus, ScienceDirect, Ovid and Google Scholar motor engine using MeSH terms of relevant keywords. During the screening phase, titles, abstracts and full texts were reviewed and risk of bias was assessed for all selected papers based on Newcastle-Ottawa Scale (NOS) checklist. The results of the primary studies were combined using meta-analysis.

RESULTS

Of 95 eligible studies entered into the meta-analysis, prevalence of BRAF gene mutation had been assessed among 19,484 primary tumour samples as well as 12,256 metastatic samples. The total prevalence of BRAF gene mutation among primary tumour samples was estimated as of 10.16% (8.09-12.22) in the world, 0.41% (0-1.89) in EMRO region, 10.06% (7.54-12.59) in EURO region, 10.33% (7.24-13.43) in SEARO region and 11.33% (7.29-15.37) in WPRO region. The pooled estimates for BRAF gene mutation in metastatic samples were 6.53% (5.09-7.96), 8.07% (5.57-10.56), 5.38% (3.75-7.02) and 5.55% (1.72-9.38) for all regions, EURO, WPRO and PAHO regions respectively.

CONCLUSION

Our results showed evidences of BRAF gene mutation in one-tenth of primary colorectal tumour samples in EURO, PAHO, SEARO and WPRO regions which was considerably higher than that of the EMRO region.

Investigation on the hereditary basis of colorectal cancers in an African population with frequent early onset cases

Background

Approximately 25% of colorectal cancer patients in sub-Saharan Africa are younger than 40 years, and hereditary factors may contribute. We investigated the frequency and patterns of inherited colorectal cancer among black Zimbabweans.

Methods

A population-based cross-sectional study of ninety individuals with a new diagnosis of colorectal cancer was carried out in Harare, Zimbabwe between November 2012 and December 2015. Phenotypic data was obtained using interviewer administered questionnaires, and reviewing clinical and pathology data. Cases were screened for mismatch repair deficiency by immunohistochemistry and/or microsatellite instability testing, and for MLH1, MSH2 and EPCAM deletions using multiplex ligation-dependent probe amplification. Next generation sequencing using a 16-gene panel was performed for cases with phenotypic features consistent with familial colorectal cancer. Variants were assessed for pathogenicity using the mean allele frequency, phenotypic features and searching online databases.

Results

Three Lynch syndrome cases were identified: MSH2 c.2634G>A pathogenic mutation, c.(1896+1_1897–1)_(*193_?)del , and one fulfilling the Amsterdam criteria, with MLH1 and PMS2 deficiency, but no identifiable pathogenic mutation. Two other cases had a strong family history of cancers, but the exact syndrome was not identified. The prevalence of Lynch syndrome was 3·3% (95% CI 0·7–9·4), and that of familial colorectal cancer was 5·6% (95% CI, 1·8–12·5).

Conclusions

Identifying cases of inherited colorectal cancer in sub-Saharan Africa is feasible, and our findings can inform screening guidelines appropriate to this setting.

Global Inequities in Precision Medicine and Molecular Cancer Research

Precision medicine based upon molecular testing is heralded as a revolution in how cancer is prevented, diagnosed, and treated. Large efforts across the world aim to conduct comprehensive molecular profiling of disease to inform preclinical models, translational research studies and clinical trials. However, most studies have only been performed in patients from high-income countries. As the burden on non-communicable diseases increases, cancer will become a pressing burden across the world, disproportionately affecting low-middle income settings. There is emerging evidence that the molecular landscape of disease differs geographically and by genetic ancestry, which cannot be explained by environmental factors alone. There is a lack of good quality evidence that characterises the molecular landscape of cancers found in low-middle income countries. As cancer medicine becomes increasingly driven by molecular alterations in high-income settings, low-income settings may become left behind. Further efforts on an international scale must be made by researchers, funders, and policymakers to ensure cancer research addresses disease across the world, so models are not limited to subtypes of disease found in high-income countries. In this review, we discuss differences found in the molecular profiles of tumours worldwide and the implication this has for the future of global cancer care. Finally, we identify several barriers currently limiting progress in this field and innovative solutions, which may address these shortcomings.

Detection of DNA Mismatch Repair Protein Abnormalities in Sudanese Colorectal Cancer Patients Using Immunohistochemical Methods

PURPOSE

DNA mismatch repair (MMR) protein abnormalities among 42 Sudanese colorectal cancer (CRC) patients were assessed.

METHODS

Sections were stained by immunohistochemical method to assess the abnormalities of MLH1, MSH2, MSH6, and PMS2.

RESULTS

Of the 42 included cases, 34 (80.95%) were MMR protein positive for all MMR proteins under assessment, 3 (7.14%) MSH2 inadequate, and 1 (2.38%) MSH6 inadequate. Abnormal MMR protein expression was found in 4 (9.5%) cases. Of these, 2 (50%) were MSH2 and MSH6 negative and 2 (50%) were MLH1 and PMS2 negative. Regarding microsatellite instability (MSI) results, the three cases that were MSH2 inadequate and positive for the rest by immunohistochemistry (IHC) showed stable results with both BAT 25 and 26. The case that was MSH6 inadequate showed stable results with both BAT 25 and 26. The 2 cases with MSH2- and MSH6-negative results were unstable with both BAT 25 and 26. Of the two cases that were MLH1 and PMS2 negative, one case showed non-evaluable results with both BAT 25 and 26 while the other case was unstable with BAT 26 and not evaluable with BAT 25.

CONCLUSIONS

The percentage of MMR protein-negative cases in Sudanese CRC patients appears to be relatively low compared to what is generally reported in certain studies in different countries. Furthermore, MLH1 and PMS2 and MSH2 and MSH6 abnormal expression detected by IHC seems to be the most common form of MMR protein abnormalities in Sudanese CRC patients. Concerning the results of IHC, MLH1 and MSH2 seem to be the most inactivated MMR genes in Sudanese CRC patients.

Emergence of Colorectal Cancer in West Africa: Accepting the Inevitable

It seems not too long ago that colon and rectal cancer is a "rare" disease in rural Africa; however, over the last 30 years in West Africa, published evidence has shown decade by decade increases in the incidence of colorectal cancer (CRC). Therefore, CRC should now be accepted as a recognized disease in native Africans; nevertheless, we must acknowledge that the incidence is a fraction of what obtains in the developed countries of Europe and America. This presentation will attempt to examine the emergence of CRC within the West African axis over the last four decades.

The shifting epidemiology of colorectal cancer in sub-Saharan Africa

The perception that colorectal cancer is rare in sub-Saharan Africa is widely held; however, it is unclear whether this is due to poor epidemiological data or to lower disease rates. The quality of epidemiological data has somewhat improved, and there is an ongoing transition to western dietary and lifestyle practices associated with colorectal cancer. The impact of these changes on the incidence of colorectal cancer is not as evident as it is with other non-communicable diseases such as diabetes. In this Viewpoint, we discuss the epidemiology of colorectal cancer in sub-Saharan Africa. Colorectal cancer in this region frequently occurs at an early age, often with distinctive histological characteristics. We detail the crucial need for hypothesis-driven research on the risk factors for colorectal cancer in this population and identify key research gaps. Should colorectal cancer occur more frequently than assumed, then commensurate allocation of resources will be needed for diagnosis and treatment.

Molecular Biomarkers of Colorectal Cancer and Cancer Disparities: Current Status and Perspective

This review provides updates on the efforts for the development of prognostic and predictive markers in colorectal cancer based on the race/ethnicity of patients. Since the clinical consequences of genetic and molecular alterations differ with patient race and ethnicity, the usefulness of these molecular alterations as biomarkers needs to be evaluated in different racial/ethnic groups. To accomplish personalized patient care, a combined analysis of multiple molecular alterations in DNA, RNA, microRNAs (miRNAs), metabolites, and proteins in a single test is required to assess disease status in a precise way. Therefore, a special emphasis is placed on issues related to utility of recently identified genetic and molecular alterations in genes, miRNAs, and various "-omes" (e.g., proteomes, kinomes, metabolomes, exomes, methylomes) as candidate molecular markers to determine cancer progression (disease recurrence/relapse and metastasis) and to assess the efficacy of therapy in colorectal cancer in relation to patient race and ethnicity. This review will be useful for oncologists, pathologists, and basic and translational researchers.

Tumor-Infiltrating Lymphocytes, Crohn's-Like Lymphoid Reaction, and Survival From Colorectal Cancer

BACKGROUND

While clinical outcomes from colorectal cancer (CRC) are influenced by stage at diagnosis and treatment, mounting evidence suggests that an enhanced lymphocytic reaction to a tumor may also be an informative prognostic indicator.

METHODS

The roles of intratumoral T lymphocyte infiltration (TIL), peritumoral Crohn's-like lymphoid reaction (CLR), microsatellite instability (MSI), and clinicopathological characteristics in survival from CRC were examined using 2369 incident CRCs from a population-based case-control study in northern Israel. Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for CRC-specific and all-cause mortality in multivariable models adjusted for age, sex, ethnicity, grade, stage, and MSI. All statistical tests were two-sided.

RESULTS

Tumors with TIL/high-powered field (HPF) of 2 or greater were associated with a statistically significant increase in CRC-specific (P < .001) and overall survival (P < .001) compared with tumors with TIL/HPF of less than 2. Similarly, tumors with a prominent CLR experienced better CRC-specific (P < .001) and overall survival (P < .001) as compared with those with no response. High TILs (HR = 0.76, 95% CI = 0.64 to 0.89, P < .001) and a prominent CLR (HR = 0.71, 95% CI = 0.62 to 0.80, P < .001), but not MSI, were associated with a statistically significant reduction in all-cause mortality after adjustment for established prognostic factors.

CONCLUSIONS

TILs and CLR are both prognostic indicators for CRC after adjusting for traditional prognostic indicators.