Difference in incidence of colorectal cancer between men and women in Asia

Molecular basis of sex differences in cancer: Perspective from Asia

Cancer is a leading cause of mortality and morbidity globally. Sex differences in cancer are evident in death rates and treatment responses in several cancers. Asian patients have unique cancer epidemiology influenced by their genetic ancestry and sociocultural factors in the region. In this review, we show molecular associations that potentially mediate sex disparities observed in cancer in Asian populations. Differences in sex characteristics are evident at the cytogenetic, genetic, and epigenetic levels mediating processes that include cell cycle, oncogenesis, and metastasis. Larger clinical and in vitro studies that explore mechanisms can confirm the associations of these molecular markers. In-depth studies of these markers can reveal their importance as diagnostics, prognostics, and therapeutic efficacy markers. Sex differences should be considered in designing novel cancer therapeutics in this era of precision medicine.

The Rise of Colorectal Cancer in Asia: Epidemiology, Screening, and Management

PURPOSE OF REVIEW

Colorectal cancer (CRC) remains the third most commonly diagnosed cancer globally, and its incidence and mortality rates have been on the rise in Asia. In this paper, we summarize the recent trends and screening challenges of CRC in this region.

RECENT FINDINGS

In 2018, Asia had the highest proportions of both incident (51.8%) and mortality (52.4%) CRC cases (all genders and ages) per 100,000 population in the world. In addition, there has been a rising trend of this disease across Asia with some regional geographic variations. This rise in CRC can be attributed to westernized dietary lifestyle, increasing population aging, smoking, physical inactivity, and other risk factors. In curbing the rising trend, Japan, South Korea, Singapore, and Taiwan have launched nationwide population-based screening programs. CRC screening across this region has been found to be effective and cost-effective compared with no screening at all. The emergence of new therapies has caused a reduction in case fatality; however, these new options have had a limited impact on cure rates and long-term survival due to the great disparity in treatment capacity/resources and screening infrastructures among Asian countries with different degrees of economic development. CRC is still rising in Asia, and implementation of screening is necessary for moderate- to high-incidence countries and construction of treatment capacity is the priority task in low-incidence and low-income countries. Unless countries in Asia implement CRC screening, the incidence and mortality rates of this disease will continue to rise especially with the rapidly rising population growth, economic development, westernized lifestyle, and increasing aging.

Postoperative complications after stapled and hand-sewn ileal pouch-anal anastomosis for familial adenomatous polyposis: A multicenter study

Ileal pouch‐anal anastomosis (IPAA) after total proctocolectomy (TPC) can be conducted with either hand‐sewn or stapled anastomosis for patients with familial adenomatous polyposis (FAP). Although stapled IPAA without mucosectomy has a higher risk for developing adenomas in the remnant mucosa, it is the simpler procedure with potential benefit in short‐term outcomes. However, it remains controversial as to whether stapled IPAA has any advantages in reducing postoperative complications. The aim of the present study was to compare the postoperative complications and short‐term outcomes of stapled and hand‐sewn IPAA for patients with FAP, using a multicenter cohort sample in Japan. Data of 143 patients with FAP who underwent TPC with stapled IPAA (n=37) and hand‐sewn IPAA (n=106) at 23 institutions between 2000 and 2012 were collected. Postoperative complications, proportion of ostomy, fecal continence and overall survival were compared. Overall rates of the Clavien‐Dindo grade II‐IV complications were not different between the two groups (19% in stapled vs 25% in hand‐sewn, P=.42), with significantly fewer pouch‐related complications including leakage, pelvic abscess, vaginal fistula and anastomotic stricture in stapled IPAA (none in stapled vs 11% in hand‐sewn, P=.036). There was no mortality. Proportion of ostomy at 12 months was similar (2.7% in stapled vs 4.3% in hand‐sewn, P=.26). Mean Wexner score was similar. (0.47 in stapled vs 2.0 in hand‐sewn, P=.12). Five‐year overall survival excluding Stage IV patients was 96% in both groups. Stapled IPAA is a safe option in patients with FAP with a potential benefit in reducing pouch‐related complications.

Label-free tissue scanner for colorectal cancer screening

The current practice of surgical pathology relies on external contrast agents to reveal tissue architecture, which is then qualitatively examined by a trained pathologist. The diagnosis is based on the comparison with standardized empirical, qualitative assessments of limited objectivity. We propose an approach to pathology based on interferometric imaging of “unstained” biopsies, which provides unique capabilities for quantitative diagnosis and automation. We developed a label-free tissue scanner based on “quantitative phase imaging,” which maps out optical path length at each point in the field of view and, thus, yields images that are sensitive to the “nanoscale” tissue architecture. Unlike analysis of stained tissue, which is qualitative in nature and affected by color balance, staining strength and imaging conditions, optical path length measurements are intrinsically quantitative, i.e., images can be compared across different instruments and clinical sites. These critical features allow us to automate the diagnosis process. We paired our interferometric optical system with highly parallelized, dedicated software algorithms for data acquisition, allowing us to image at a throughput comparable to that of commercial tissue scanners while maintaining the nanoscale sensitivity to morphology. Based on the measured phase information, we implemented software tools for autofocusing during imaging, as well as image archiving and data access. To illustrate the potential of our technology for large volume pathology screening, we established an “intrinsic marker” for colorectal disease that detects tissue with dysplasia or colorectal cancer and flags specific areas for further examination, potentially improving the efficiency of existing pathology workflows.

Feasibility of laparoscopic total proctocolectomy with ileal pouch-anal anastomosis and total colectomy with ileorectal anastomosis for familial adenomatous polyposis: results of a nationwide multicenter study

BACKGROUND

Data supporting the safety and feasibility of laparoscopic total proctocolectomy with ileal pouch-anal anastomosis (TPC-IPAA) and total colectomy with ileorectal anastomosis (TC-IRA) for patients with familial adenomatous polyposis (FAP) are limited. The aim of this study was to clarify the feasibility and morbidity of laparoscopic TPC-IPAA and TC-IRA for patients with FAP, using a large Japanese multicenter dataset.

METHODS

Data on 256 patients with FAP who underwent TPC-IPAA (n = 171) or TC-IRA (n = 85) at 23 institutions between the years 2000 and 2012 were collected. Short- and long-term clinical outcomes were compared between laparoscopic and open approaches for each procedure.

RESULTS

Among the 256 patients with FAP, a total of 126 patients underwent laparoscopic surgery, consisting of 74 laparoscopic TPC-IPAAs and 52 laparoscopic TC-IRAs. The proportion of the FAP patients who underwent laparoscopic surgery increased during the study period, reaching 79 % of all TPC-IPAAs and 82 % of all TC-IRAs in the final two years covered by the data. In both TPC-IPAA and TC-IRA, the laparoscopic approach was associated with a longer operative duration but a similarly low postoperative morbidity and comparably adequate anal function compared with the open approach. The overall survival and the incidence of desmoid tumor were also comparable between the laparoscopic and open approaches in both procedures.

CONCLUSIONS

Laparoscopic TPC-IPAA and TC-IRA are both feasible options-with low rates of morbidity, good functional outcomes, and excellent overall survival rates-in patients with FAP. Since the data indicate that laparoscopic TPC-IPAA and TC-IRA are feasible, they also support the recent increase in laparoscopic surgery for patients with FAP in Japan.

Ulcerative colitis-associated colorectal cancer shows a poorer survival than sporadic colorectal cancer: a nationwide Japanese study

BACKGROUND

The clinicopathological features of ulcerative colitis-associated colorectal cancer (UC-CRC) have not yet been fully clarified, especially in Asian populations. This study aimed to clarify the prognosis and clinicopathological features of UC-CRC in comparison with sporadic CRC in the Japanese population.

METHODS

Histologically diagnosed UC-CRC patients between 1978 to 1998 were extracted from the Multi-Institutional Registry of Large-Bowel Cancer in Japan, a large nationwide CRC database, and the clinicopathological features and postoperative survival rates of UC-CRC patients and sporadic CRC patients were compared.

RESULTS

Among the 108,536 CRC patients registered between 1978 and 1998, a total of 169 UC-CRC patients were identified, including 121 patients who had been treated surgically. The proportion of UC-CRC patients increased in the period between 1995 and 1998 compared to that between 1978 and 1994. Comparisons with the sporadic CRC patients showed that the UC-CRC patients were younger, had a higher proportion of multiple cancer lesions, had higher proportions of superficial type lesions and invasive type lesions morphologically, and had higher proportions of mucinous or signet ring cell carcinomas. In stage III, UC-CRC patients had a poorer survival rate than the sporadic CRC patients (43.3% versus 57.4%, P = 0.0320).

CONCLUSIONS

UC-CRC increased over the investigated time periods and showed a poorer survival than sporadic CRC in the advanced stage, while no difference was observed in the early stage. By detecting UC-CRC at an early stage we can expect a similar postoperative outcomes to that of sporadic CRC. These results stress the importance of surveillance for the early detection of UC-CRC.

Vascular endothelial growth factor 1498C/T, 936C/T polymorphisms associated with increased risk of colorectal adenoma: a Chinese case-control study

Single nucleotide polymorphisms in vascular endothelial growth factor gene VEGF, 1498C/T and 936 C/T are associated with colorectal cancer. We sought to determine whether such genetic variability in VEGF contributes to susceptibility of colorectal adenoma (CRA), a presumably precancerous state of colorectal cancer. In this research, two aforementioned polymorphisms were investigated for CRA susceptibility in a Chinese case-control study. The epidemiological risk factors were collected through questionnaire. The plasma VEGF levels were measured via enzyme-linked immunosorbent assay (ELISA). The Taqman-Probe assay was used to determine genotypes in 224 CRA patients and 200 CRA-free controls. The clinicopathological data of each sample were collected for further correlation analysis. According to data analysis males, cigarette smokers, patients who carry metabolic syndrome or familial antecedent of adenomas were significantly associated with CRA risk. Plasma VEGF levels of CRA patients were higher than those of controls (P = 0.003). This difference is independent of genotypes. The carriers with 936CT and CT+TT had higher risk of CRA in comparison with controls (CT vs. CC, OR 2.00, 95% CI 1.23-3.25, P = 0.006; CT+TT vs. CC, OR 2.04, 95% CI 1.28-3.26, P = 0.003). 936-T allele was associated with increased risk of CRA (OR 1.91, 95% CI 1.25-2.91, P = 0.003). Both CRA and control show no difference in the genotype of 1498C/T and the allele frequency of C-/T-. CRA patients with haplotype 1498T+936T presented significantly higher risk than those with wild-type 1498T+936C. Moreover, patients carrying 936CT+TT and 936-T allele demonstrated a tendency for villous adenoma. CRA patients have elevated plasma VEGF levels. The VEGF 936C/T polymorphism and 1498T+936T haplotype were found to be associated with increased CRA susceptibility.