Prospective analysis of colorectal carcinoma. Determination of an age-site and stage relationship and the correlation of DNA index with clinicopathologic parameters

Anatomical distribution of colorectal carcinoma in Iran: a retrospective 15-yr study to evaluate rightward shift

BACKGROUND

Although more than two third of colorectal cancers are localized on the left side, recent studies suggest a right ward shift in anatomical distribution with increase in proximal colon cancers. The aim of the present study was to determine the anatomical distribution of colorectal cancer in a referral center over a 15 year period.

METHOD

Records of patients who underwent colectomy in the Cancer Institute of Iran from 1994 to 2009 were retrieved. Data including anatomical localization, year of diagnosis, patient age and gender, tumor histology and differentiation, and disease stage were extracted. Tumors located from the cecum to the distal transverse colon were classified as right side and those occurring from the splenic flexure to the descending colon as left-sided. Cancer of rectum and recto-sigmoid junction were considered as rectal cancers.

RESULTS

A total of 442 patients including 220 (49/8%) men and 222 (50/2%) women with mean age 53 were included. Most patients were in stages II and III (47.1% and 33% respectively). There were 157 (35.5 %) colon cancers and 285 (64.5%) rectal cancers. 43.3% of the colon cancers were right sided and 56.7% were left sided. There was no statistically significant increase in right sided cancer during the period of the study. There were no significant differences in age at diagnosis, gender, grade and stage of tumor between the right and the left sided cancers.

CONCLUSION

No proximal shift over time was identified in our study.

Colorectal carcinoma in young adults: a retrospective study on Indian patients: 2000-2008

AIM

To highlight an increased incidence of colorectal cancer (CRC) amongst young Indian adults.

METHOD

A retrospective study of 305 cases of CRC admitted to SSKM Hospital, Kolkata, India during 2000-2008 was carried out.

RESULTS

The ratio (0.64) of under-40 to above-40 CRC patients reported in this study is comparable to those from premier Oncology Centers in India (∼0.52) and is higher than those in the Indian National Cancer Registry (∼0.20) and international average (0.07). Distinctive tumour characteristics in younger patients including left-sided lesion (69.7%), presentation at an advanced (III/IV) stage (60%), poor histological differentiation (50%) and predominance of mucin-secreting adenocarcinoma (80%) are similar to those reported in the international literature. Some features are suggestive of hereditary non polyposis colorectal cancer syndrome, which may be a possible reason for the high proportion of young CRC patients.

CONCLUSION

A high index of suspicion for CRC among young Indian adults is necessary.

Colorectal carcinoma: a retrospective, descriptive study of age, gender, subsite, stage, and differentiation in Iran from 1995 to 2001 as observed in Tehran University

PURPOSE

Colorectal carcinoma is one of the most common cancers in the world as well as in Iran. There are differences in subsite of the carcinoma when considering age and gender. This study was designed to describe the distribution of colorectal carcinoma by age at diagnosis, gender, and subsite of the tumor. These factors also are evaluated in conjunction with disease stage and tumor differentiation at the time of diagnosis.

METHODS

Data from 419 patients from a population that receives no screening between April 1995 and March 2001 operated on in the Cancer Institute and Imam Khomieni Hospital with a diagnosis of colorectal cancer were used to describe distribution of the colorectal carcinoma by age, gender, tumor subsite and pathology, and stage at diagnosis.

RESULTS

There were 403 (96.2 percent) cases of adenocarcinoma. Males and females constituted 52.4 and 47.6 percent of cases, respectively. The mean age was 52.3 years. Patients were divided into two age groups (40 years and younger, and older than 40 years); 16.4 percent of patients had tumors in the proximal colon and 83.6 percent in distal parts. Most patients were Stage II and III (48.1 and 33.4 percent, respectively). Tumor subsite distribution was almost the same between the two age groups (aged 40 years and younger: proximal, 18.5 percent, and distal, 81.5 percent; older than aged 40 years: proximal, 15.7 percent, and distal, 84.3 percent). Most patients in the younger age group were Stage III (45 percent) and in the older age group were Stage II (53.2 percent; P<0.001). Tumor differentiation proportions in patients aged 40 years and younger were: good, 24.4 percent; moderate, 53.6 percent; poor, 22 percent; and in patients older than aged 40 years were: good, 41.5 percent; moderate, 52.6 percent; poor, 5.9 percent (P<0.001). There were no differences in stage and tumor differentiation between two genders, but most of the patients with tumors in proximal colon were males (62.5 percent; P=0.1).

CONCLUSIONS

Most of the colorectal carcinomas were in distal parts in our study, so most of these carcinomas can be detected by proctosigmoidoscopy. Because younger patients had more advanced disease, the importance of screening and "clinical suspicion" in the young is important.

Age-related variations in progression of cancer at diagnosis and completeness of cancer registry data

There is some evidence that stage and grade at diagnosis of cancer decreases with age and that the availability of data on stage and grade of cancer decreases with age. This may be because older people tend to receive less intensive investigation of cancer but this has not been confirmed. We investigated the relationship between age at diagnosis of cancer and both stage and grade at diagnosis, and the chances of data on stage or grade at diagnosis being unavailable, in people with colorectal cancer (n=12,419) and women with breast cancer (n=12,793) using 2 years of cancer registry data from the north of England. Stage and grade decreased with increasing age in colorectal cancer. Grade decreased but stage increased with increasing age in women with breast cancer. The chances of data on stage and grade at diagnosis being unavailable increased with age in all cases.

DNA ploidy in colorectal cancer, heterogeneity within and between tumors and relation to survival

Flow cytometry was used to study the incidence of aneuploidy and to determine the significance of multiple sampling from colorectal tumors. DNA ploidy pattern has been proposed as a supplementary prognostic marker, but discrepancies in findings are major. DNA clonal heterogeneity, defined as two or more DNA aneuploid stemlines in the same tumor, is well established. However, most studies have been based on only one biopsy from each tumor. In our study multiple biopsies were taken from 163 patients (88 males and 75 females) electively operated for colorectal cancer. Tumor cells were harvested by fine needle aspiration from fresh frozen biopsies sampled at different sites of each tumor. DNA aneuploidy was detected in tumors from 145 patients (89%), and 18 patients (11%) had a solitary DNA diploid cell population. In a 79 month follow-up period 105 patients had died. Statistical analysis showed that distinction between diploidy and aneuploidy did not predict survival. However, grouping subpopulations into DNA diploid plus near diploid (DNA index (DI) 0. 97-1.15), DNA aneuploid with all aneuploid subpopulations in the interval 1.15-2.06, and DNA aneuploid with subpopulations with DI < 0.97 and/or DI > 2.06, showed a significant difference in survival in a Cox multivariate analysis including Dukes' stage P = 0.049 comparing the second group to the first and P = 0.01 comparing the third group to the first. In 21 (13%) patients only one subpopulation was found, 57 (35%) had two, 44 (27%) had three, and 41 (25%) had four or more different subpopulations. The association of DNA ploidy to survival is shown to be dependent on the number of biopsies analysed.