Survivorship from large bowel cancer among Caucasians and Japanese in Hawaii

Comparison of characteristics and survival of colorectal cancer between Japanese-Americans in Hawaii and native Japanese in Japan

PURPOSE

This study was designed to investigate whether characteristics, prognostic risk factors, and survival of colorectal cancer of Japanese-Americans in Hawaii are different from those of native Japanese in Japan.

METHODS

A retrospective review of patients with colorectal cancer surgically resected in single institutions in Hawaii and Japan from 1996 to 2002.

RESULTS

A total of 410 Japanese-American patients (218 males; median age, 73 years) and 621 native Japanese patients (382 males; median age, 65 years) were included. There were significant differences in age (P < 0.001), age distribution (P < 0.001), gender (P = 0.008), preoperative carcinoembryonic antigen (P < 0.001), and anatomic site distribution (P < 0.001). The tumor characteristics of Japanese-American patients were close to the general American population compared with the Surveillance, Epidemiology, and End Results data. There were no differences in tumor size, histologic grade, each of T, N, M status and TNM stage between the two groups. The overall five-year survival rates (Japanese-Americans, 75.5 percent; native Japanese, 76.2 percent; P = 0.55) and survival rates in each of four stratified stages were similar. Risk factors associated with survival were not different, except for carcinoembryonic antigen (P = 0.036).

CONCLUSIONS

In patients with colorectal cancer in Japanese-Americans in Hawaii, some of tumor characteristics have changed from those of native Japanese in Japan. However, there are no remarkable differences in prognostic factors and survival between the two groups. The present study suggests that certain changes of colorectal cancer characteristics that were seen in Japanese-American may occur in native Japanese in Japan in the near future, although the survival outcome of colorectal cancer may remain the same.

Time dependent ethnic convergence in colorectal cancer survival in Hawaii

BACKGROUND

Although colorectal cancer death rates have been declining, this trend is not consistent across all ethnic groups. Biological, environmental, behavioral and socioeconomic explanations exist, but the reason for this discrepancy remains inconclusive. We examined the hypothesis that improved cancer screening across all ethnic groups will reduce ethnic differences in colorectal cancer survival.

METHODS

Through the Hawaii Tumor Registry 16,424 patients diagnosed with colorectal cancer were identified during the years 1960-2000. Cox regression analyses were performed for each of three cohorts stratified by ethnicity (Caucasian, Japanese, Hawaiian, Filipino, and Chinese). The models included stage of diagnosis, year of diagnosis, age, and sex as predictors of survival.

RESULTS

Mortality rates improved significantly for all ethnic groups. Moreover, with the exception of Hawaiians, rates for all ethnic groups converged over time. Persistently lower survival for Hawaiians appeared linked with more cancer treatment.

CONCLUSION

Ethnic disparities in colorectal cancer mortality rates appear primarily the result of differential utilization of health care. If modern screening procedures can be provided equally to all ethnic groups, ethnic outcome differences can be virtually eliminated.

Racial and socioeconomic status differences in survival of colorectal cancer patients in Hawaii

The study reported here examines the survival experience up to 84 months of patients from the five major racial groups in Hawaii diagnosed with colorectal cancer during the years between 1960 and 1974 based on data in the Hawaii Tumor Registry. Previous research in Hawaii showed that racial differences in survival existed even after adjusting for sex, age at diagnosis, stage of the disease at diagnosis, and normal life expectancy. In this paper, socioeconomic status differences between racial groups are hypothesized as a possible explanation for these survival differences. The results show that socioeconomic status did account for some survival differences between racial groups beyond what could be explained by the other variables. After adjusting for all the covariates, the only statistically significant racial differences which remained were higher survival rates for the Japanese patients compared with the rates for the Hawaiian and Filipino patients. Socioeconomic status was not found, however, to have a statistically significant effect on survival independent of race or the other variables examined. Reasons for the modest effects of socioeconomic status in this study are discussed.

Survival of colorectal cancer patients in relation to duration of symptoms and other prognostic factors

The effect of duration of symptoms and other prognostic factors on survival was studied by interview using a population-based sample of 154 colorectal cancer patients. The authors found that symptom durations of up to approximately one year before diagnosis had no effect on survival. In addition, it was found that the total number of symptoms was a statistically significant predictor of survival, although no single symptom had a significant effect. Stage, sex, and site also were found to be significant predictors of survival, whereas age, socioeconomic status, and other factors were not predictive.