Surgical pathology of colorectal cancer in Filipinos: implications for clinical practice

Colonic schistosomiasis: A case report

BACKGROUND

Schistosomiasis is a chronic parasitic infection endemic in many countries. Colonic schistosomiasis is a rare entity with no specific clinical manifestations or endoscopic aspects, which delays the diagnosis. Diagnosis is primarily dependent on histopathological analysis, and treatment with antihelminthics typically resolves the infection.

CASE SUMMARY

We present the case of a 21-year-old male who suffered from chronic diarrhea and abdominal pain. Physical examination found no abnormalities, blood tests were normal, and stool examination was negative. A colonoscopy revealed a nodular terminal ileal mucosa, two cecal polypoid lesions with no particular surface pattern, and millimetric erosions in the rectum. The presence of Schistosoma eggs with thick peripheral capsules and viable embryos inside and numerous eosinophils surrounding the egg capsule were observed on histopathological examination. The patient received praziquantel, and his symptoms were resolved.

CONCLUSION

Colonic schistosomiasis should be considered as a differential diagnosis, especially in endemic countries. Endoscopy and histopathological examination can confirm the diagnosis, and antihelminthics are an effective treatment.

Clinicopathologic Factors Associated with Mismatch Repair Status Among Filipino Patients with Young-Onset Colorectal Cancer

Introduction

Young-onset colorectal cancer is recognized as a distinct disease that may be sporadic or hereditary in nature. Microsatellite instability testing is recommended as a routine procedure in evaluating colorectal cancer specimens, especially in young-onset disease, because of implications in management. Immunohistochemistry of mismatch repair proteins serves as an inexpensive alternative to microsatellite instability testing with the added advantage of monitoring protein expression levels that may suggest underlying genetic or epigenetic alterations. This descriptive study aimed to determine the frequencies of proficient and deficient mismatch repair status among Filipino young-onset colorectal cancer patients, and to investigate their clinicopathologic profile.

Methods

Tumor tissues were prospectively collected from patients from two tertiary hospitals in the Philippines. Patients of age ≤45 years with resected adenocarcinoma of the colon or rectum were recruited.

Results

Seventy-seven out of 124 patients had tumor samples sent for immunohistochemistry. Of these, 61 samples (79%) were found to have proficient status while 16 samples (21%) had deficient status. Mismatch repair protein deficiencies, when present, more commonly involved MSH2 and MSH6 (9%) rather than MLH1 and PMS2 (5%). The deficient group had a mean age of 37.1 years and a female preponderance (56.25%), presenting as locally advanced ascending or descending colon tumors with mucinous histology in half of the population. The mismatch repair proficient group presented as locally advanced rectal and sigmoid tumors but with fewer mucinous adenocarcinomas (26.2%) compared to the deficient group. In both the mismatch repair proficient and deficient patients with family history reports, most did not have any known relative with cancer (75.4% and 68.75%, respectively).

Conclusion

This is the first attempt to perform mismatch repair testing among young-onset colorectal cancer patients in the Philippines and to gather data on their clinicopathologic characteristics. However, the limited sample size precludes conclusive results for the associations of mismatch repair with clinicopathologic features.

NRAS mutant E132K identified in young-onset sporadic colorectal cancer and the canonical mutants G12D and Q61K affect distinct oncogenic phenotypes

Recent data show a global increase in colorectal cancer (CRC) cases among younger demographics, which portends poorer prognosis. The cause of rising incidence is uncertain, and its mutational landscape remains largely unexplored, including those in genes of the epidermal growth factor receptor pathway. Among these are NRAS mutants where there is paucity of functional studies compared to KRAS. Here, the novel NRAS mutant E132K, identified in three tumor samples from Filipino young-onset, sporadic colorectal cancer patients, was investigated for its effects on different cancer hallmarks, alongside the NRAS canonical mutants G12D and Q61K which are yet poorly characterized in the context of CRC. The novel NRAS mutant E132K and the canonical G12D and Q61K mutants show resistance to apoptosis, cytoskeletal reorganization, and loss of adhesion. In contrast to activating KRAS mutations, including the analogous KRAS G12D and Q61K mutations, all three NRAS mutants have no apparent effect on cell proliferation and motility. The results highlight the need to characterize isoform- and mutation-specific oncogenic phenotypes which can have repercussions in disease management and choice of therapeutic intervention. Further analyses of young-onset versus late-onset CRC datasets are necessary to qualify NRAS E132K as a biomarker for the young-onset subtype.

Outcomes of surgical treatment of primary signet ring cell carcinoma of the colon and rectum: 22 cases reviewed with literature

Colorectal primary signet ring cell carcinoma (PSRCCR) is a rare entity with a dismal prognosis, mainly because of delayed diagnosis. The objective of this study was to investigate the clinicopathologic features and prognostic factors for PSRCCR. This is a retrospective study including the data of 22 patients with PSRCCR who underwent surgery. Patients were categorized by age, sex, tumor site, and stage. Fifteen patients were male. Median age was 40 years. Sites for metastases were lymph nodes (86.4%), peritoneum (40.9%), and liver (9.1%). Most of the patients (91%) had stage III or IV tumors. The rates of curative and palliative resections performed were equal. Mean overall survival and mean progression-free survival times were found to be 33.3 ± 7.1 months (95% confidence interval, 19.4-47.2 months) and 11.8 ± 3.5 months (95% confidence interval, 4.9-18.7 months), respectively. It was concluded that site of the tumor, presence of bowel obstruction, peritoneum and lung metastases, adjacent organ infiltration, TNM stage, and efficiency of surgery have significant effects on survival. All in all, these aggressive tumors are generally diagnosed at advanced stages. Depending on the situation, survival is shorter. A high degree of vigilance is required for these patients to avoid the negative impact of late diagnosis on survival.

Insight into mucinous colorectal carcinoma: clues from etiology

The prognostic impact of mucinous carcinoma (MC) in colorectal cancer (CRC) has been subject to debate ever since the introduction of the classification of tumors according to their histological differentiation. MC is a distinct clinical and pathological entity within the spectrum of CRC and accounts for approximately 10-15 % of cases. Factors involved in MC development have not been completely understood, but clinical observations may lead to a better insight into the etiology of MC. In this article, we provide an in-depth review of the literature regarding etiological aspects of MC. We show that there are worldwide differences in the prevalence of MC, with low rates in Asian countries and higher rates in the western world. Moreover, MC is more commonly diagnosed in patients suffering from inflammatory bowel diseases or Lynch syndrome and an increased rate of MC is observed in patients with radiotherapy-induced CRCs. These findings are suggestive of a different oncogenic development. Identification of conditions that are associated with MC generates insight into the etiological pathways leading to the development of this special subtype.

Cancer survival differences between European countries and an urban population from the Philippines

BACKGROUND

The EUROCARE study has disclosed large variations of survival across Europe, with the magnitude varying, depending on cancer site. Comparisons of these rates with those from the developing countries are rare, but important in evaluating international cancer care discrepancies. This study aimed to provide up-to-date estimates of cancer survival in a Philippine urban population, and to compare these with those observed in the European countries.

METHODS

Using the results from the EUROCARE-4 study, the survival estimates of the European patients who were diagnosed in 1995-99 and followed till December 2003 were abstracted. From randomly selected samples drawn from the Manila and Rizal Cancer Registries, 5-year survival was estimated for nine common cancers. Age-adjusted survival estimates were then compared between the Philippine population and Europeans.

RESULTS

In comparison to the European mean, survival estimates for the Philippine residents were lower for most cancers, with differences ranging from 2 to 40% units. Differences with European country-specific estimates were large for cancers of the breast and cervix, where early detection is possible, and for leukaemia, where treatment regimens are costly, highlighting the importance of health care. Smaller discrepancies were observed for stomach, liver and lung cancers, with the 5-year relative survival being similar to the Philippines and to many European countries. A survival advantage was seen though for the Philippine residents for ovarian cancer.

CONCLUSION

Apart from efforts to prevent cancers, improvements in cancer control and making early diagnosis and treatment more accessible remain major challenges, both in the Philippines and in the European nations.

Inter-country and ethnic variation in colorectal cancer survival: comparisons between a Philippine population, Filipino-Americans and Caucasians

BACKGROUND

Previous population-based studies showed differences in international and within country colorectal cancer survival estimates, but few investigated the role of prognostic factors. Using a "high resolution approach", we aimed to determine the effect of ethnicity and health care by comparing Filipino-Americans with Philippine residents, who have the same ethnicity, and with Caucasians living in the US, who have the same health care system.

METHODS

Using databases from the Manila and Rizal Cancer Registries and the United States Surveillance, Epidemiology and End Results, age-adjusted five-year absolute and relative survival estimates were computed and compared between Filipino-American colorectal cancer patients, cancer patients from the Philippines and Caucasian patients. Cox proportional hazards modelling was used to determine factors affecting survival differences.

RESULTS

Much lower 5-year relative survival estimates were obtained for Philippine residents (37%) as compared to those in Filipino-Americans (60.3%) and Caucasians (62.4%). Differences in age, stage and receipt of surgery explained a large proportion of the survival differences between Philippine residents and Filipino-Americans. However, strong excess risk of death for Philippine residents remained after controlling for these and other variables (relative risk, RR, 2.03, 95% confidence interval, 95% CI, 1.83-2.25).

CONCLUSIONS

Strong survival disadvantages of Philippine residents compared to Filipino-American patients were disclosed, which most likely reflect differences in access to and utilization of health care. Health education and advocacy, for both patients and health practitioners, should likewise be given priority.

Endoscopic findings and clinicopathologic characteristics of colonic schistosomiasis: A report of 46 cases

AIM: To make a retrospective analysis of endoscopy findings and clinicopathologic characteristics of colonic schistosomiasis in order to further improve our understanding of the disease and decrease its misdiagnosis.

METHODS: Endoscopy findings and clinicopathologic characteristics of 46 intestinal schistosomiasis patients were retrospectively analyzed. All the patients underwent colonoscopy and all biopsy specimens stained with hematoxylin and eosin were observed under a light microscope.

RESULTS: Of the 46 colonic schistosomiasis patients, 1 was diagnosed as acute schistosomal colitis, 16 as chronic schistosomal colitis and 29 as chronic active schistosomal colitis according to their endoscopic findings and pathology. Not all patients were suspected of or diagnosed as colonic schistosomiasis. Of the 12 misdiagnosed patients, 4 were misdiagnosed as ulcerative colitis, 1 as Crohn’s disease, and 7 as ischemic colitis. The segments of rectum and sigmoid colon were involved in 29 patients (63.0%). Intact Schistosoma ova were deposited in colonic mucosa accompanying infiltration of eosinocytes, lymphocytes, and plasma cells in acute schistosomal colitis patients. Submucosal fibrosis was found in chronic schistosomal colitis patients. Among the 17 patients with a signal polyp, hyperplastic polyp, canalicular adenoma with a low-grade intraepithelial neoplastic change, tubulovillous adenoma with a high-grade intraepithelial neoplastic change were observed in 10, 5, and 2 patients, respectively. Eight out of the 46 patients were diagnosed as colonic carcinoma.

CONCLUSION: Endoscopy contributes to the diagnosis of colonic schistosomiasis although it is nonspecific. A correct diagnosis of colonic schistosomiasis can be established by endoscopy in combination with its clinicopathologic characteristics.

Young-age onset of colorectal cancer in Israel

AIM

The study was conducted to investigate the differences in clinical-pathological, ethnic, and demographic presentations and the expression of mismatch repair proteins in a cohort of young-onset (</=50 years) versus late-onset Israeli patients (>50 years) with colorectal cancer.

MATERIALS AND METHODS

Clinical, demographic, and histopathological data of patients with colorectal cancer were collected retrospectively from medical records and pathology reports.

RESULTS

Ninety patients, 50 years of age or younger with a mean age of 42 years were compared with a group of 190 patients above 50 years of 50 (see Table 1). Sixty percent of the young-onset patients were females, compared to 40% in the older age group (P = 0.02). Twenty-one percent of the young-onset patients were Arabs as compared to 2% of older-onset patients (P = 0.001). Younger patients displayed a higher percentage of mucinous cancers and a higher percentage of diagnosis at an advanced stage of disease; 40% of young-onset versus 31% of older-onset patients presented Duke's stages C and D (P = 0.02).

CONCLUSIONS

Younger age of onset colorectal cancer in our cohort of Israeli patients is associated with higher percentage of Arab patients, mucinous cancers, female gender, and advanced stage at diagnosis.

Primary signet-ring cell carcinoma mimicking segmental Crohn's colitis

Primary signet-ring cell carcinoma of the colon is a rare entity with a dismal prognosis, mainly due to a delay in diagnosis. Here, we present a case of a 30-year-old Filipino woman who presented with symptoms mimicking inflammatory bowel disease. A barium enema and colonoscopy demonstrated a stricture in the rectosigmoid region. A biopsy revealed granulomatous changes indicative of inflammatory bowel disease. Despite initial improvement of her symptoms on total parenteral nutrition and steroids, the patient relapsed several weeks later with recurrent left lower quadrant pain. A subsequent biopsy revealed poorly differentiated signet-ring cell carcinoma of the colon. She was treated surgically with a left hemi-colectomy and primary repair. A high degree of suspicion is necessary to correctly diagnose these, often young, patients with primary signet-ring cell carcinoma early and have a positive impact on survival. The literature on primary signet-ring cell carcinoma is reviewed.

Clinical and molecular biologic characteristics of early-onset versus late-onset colorectal carcinoma in Filipinos

A case-control study of Filipino patients who underwent surgical resection for colorectal cancer (CRC) during a 1-year period was undertaken. Thirty-five patients under age 40 years were identified. Paraffin blocks of these and 35 randomly selected patients over age 40 underwent histologic and immunohistochemical evaluation. Markers chosen for evaluation included the apoptosis-associated gene products (p53 and bcl-2), a tumor proliferation activity-related factor (Ki-67), and the markers (MLH1 and MSH2) of DNA microsatellite instability (MSI). Results were correlated with age and the stage and location of the tumor. The average age of the early-onset group was 30.7 years compared to the late-onset group at 67.0 years; and the male/female ratio was equivalent. The younger patients had a significantly higher Dukes' stage, the tumors were more poorly differentiated, and they were more frequently of the mucinous and signet ring cell histopathologic type. Expression of p53 was higher in the younger patients ( p < 0.001) and was independent of the degree of differentiation or the stage of the tumor. No differences of expression were noted for the other markers measured. The increased frequency of CRC in Filipino patients less than 40 years of age offers a unique opportunity to gain a better understanding of carcinogenesis, which might be exploited during diagnosis and management. The differences noted between the early- and late-onset CRC are provocative and provide an impetus for increased screening in Filipinos.