Cancer incidence and incidence rates in Japan in 1996: estimates based on data from 10 population-based cancer registries

Effect of Medical Educational Lectures by Pharmacists for Understanding and Relieving Post-laryngectomy Symptoms

Patients who underwent total laryngectomy (TL) are limited in their access to health information and have reduced quality of life because of difficulties in communicating with health providers. Understanding the method for coping with symptoms after TL is important to self-control. However, their understanding and relief regarding the method including medicine use are not well known. In this study, we conducted a current situation survey about symptoms after TL and held medical educational lectures (ML) by pharmacists for the patients. We used one questionnaire to survey the present situation and another to evaluate the understanding and relieving about the method including medicine use for coping with four symptoms, such as constipation, insomnia, having phlegm, and skin dryness before and after ML. Most participants had one or more symptoms and felt there was a communication barrier between them and their health provider. The participants felt inadequate understanding and relief before the ML, but these were improved after ML. There was a positive correlation between the understanding and relief before ML. In conclusion, the participants might not feel relief of four symptoms because of inadequate understanding of the method including medicine use for coping with their symptoms. Grasping the current situation and medication use of patients after TL by pharmacists will be helpful for appropriate medication use.

Synchronous and Metachronous Colon Cancers in Patients with Gastric Cancer: Report of 2 Cases

Colorectal cancer is the most common synchronous or metachronous cancer in patients with gastric cancer. I report two cases of synchronous and metachronous colon cancer with gastric cancer. Case 1: A 70-year-old man was admitted to our hospital for the treatment of gastric cancer, which had been diagnosed during esophagogastroduodenoscopy (EGD) screening. The recommended preoperative testing was colonofiberscopy (CFS). The CFS revealed a 3-cm ulcerofungating mass, located 20 cm from the anal verge. The pathological report showed a well-differentiated adenocarcinoma. Consequently, we performed radical total gastrectomy and low anterior resection simultaneously. There was no recurrence during the 40-month follow-up of this individual on an out-patient basis. Case 2: A 71-year-old man who was treated with laparoscopically assisted distal gastrectomy (LADG) due to early gastric cancer underwent regular follow-up examination with EGD and abdominopelvic computed tomography. A CFS performed 5 years after the LADG revealed a polypoid mass in the sigmoid colon. The pathological report showed a villous adenoma with adenocarcinoma in situ. The patient underwent a colonofiberscopic mucosectomy. At 36 months after the endoscopic mucosectomy, the patient remained free of recurrence.

Evaluation of the seventh edition of the tumour, node, metastasis (TNM) classification for colon cancer in two nationwide registries of the United States and Japan

AIM

The new TNM classification is currently being implemented. We evaluated the TNM-7 staging system based on the two nationwide colon cancer registries in the United States and Japan to clarify whether this system better stratifies patients' prognoses than the TNM-6 did and to determine whether stratification can be effectively simplified.

METHODS

The Surveillance, Epidemiology, and End Results population-based data from 1988 to 2001 for 50139 colon cancer patients and the multi-institutional registry data from the Japanese Society for Cancer of the Colon and Rectum from 1984 to 1994 for 10754 patients were analysed. We devised a modified version of the TNM-7 staging system to allow simpler classification of the TN categories and compared the TNM-6, TNM-7, modified TNM-7, and the Dukes staging system based on survival curves and objective statistical tests such as likelihood ratio χ(2) tests, Akaike's information criterion, and Harrell's c-index.

RESULTS

The TNM-7 was superior to the TNM-6 in all objective statistical tests in the United States (c-index; 0.700 vs 0.696, P<0.001) as well as in the Japan data sets (0.732 vs 0.729, P=0.035). The modified TNM-7 is much simpler, but it nevertheless showed similar values to those of the original TNM-7 (c-index; the United States 0.702, Japan 0.733).

CONCLUSIONS

  The new TNM-7 is complicated but better at stratifying patients than the TNM-6 in the United States and Japan, and could be effectively simplified.

Expression and function of CXCR4 in human salivary gland cancers

Salivary gland cancers (SGCs) frequently metastasize to cervical lymph nodes and distant organs. Currently, the mechanisms responsible for the metastatic behavior of SGC cells are not fully understood. We previously demonstrated that the stromal cell-derived factor-1 (SDF-1; also known as CXCL12)/CXCR4 system is involved in the establishment of metastasis in oral squamous cell carcinoma. In the present study, we investigated the role of CXCR4 in the metastatic behavior of SGCs. We examined the expression of CXCR4 mRNA and protein in human SGC cell lines by quantitative RT-PCR and western blotting, respectively. The expression of CXCR4 mRNA and protein were frequently upregulated in 5 out of 6 SGC cell lines. Functional CXCR4 expression was demonstrated by the ability of these SGC cell lines to migrate toward an SDF-1 gradient. SDF-1 rapidly activated extracellular signal-regulated kinase (ERK)1/2 in SGC cell lines. Immunohistochemical analysis revealed that CXCR4 protein expression was detected in either the nucleus or cytoplasm of cancer cells in 16 out of 20 tissues of adenoid cystic carcinoma (ACC) and in 4 out of 6 tissues of mucoepidermoid carcinoma, which are representative of SGC. Furthermore, ACC cell lines exhibited dramatic metastasis to the lung following intravenous inoculation, whereas AMD3100, a CXCR4 antagonist, significantly inhibited lung metastasis of the cells, ameliorated body weight loss and improved the survival rate of tumor-bearing nude mice. These results indicate that CXCR4 expression contributes to the metastatic potential of SGCs.

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.

Improvement of long-term survival of colorectal cancer in Japanese-Americans of Hawaii from 1990 to 2001

BACKGROUND

To compare the long-term survival of colorectal cancer (CRC) during two 6-year periods using patients with similar characteristics of the same ethnicity in Hawaii.

METHODS

A retrospective review of Japanese-American patients in Hawaii with CRC surgically resected and followed more than 5 years in a single institution. Patients were divided into two groups by date that patients had surgery: Group 1; 1990-1995, and Group 2; 1996-2001 (introduction of newer chemotherapy, aggressive surgery for liver metastases including radiofrequency thermal ablation).

RESULTS

A total of 344 patients in Group 1 (median age 69.5 years) and 330 patients in Group 2 (median age 71.7 years) were included. There were no differences between two groups in gender, age, anatomic site, carcinoembryonic antigen, tumor size, histologic grade, and TNM stage distribution, including pT, pN, and pM status. Overall 5-year survival rate difference approached significance between two groups (Group 1: 73.2% vs. Group 2: 78.9%; p = 0.097). Particularly, there was significant difference in stage IV patients (Group 1; 8.7% vs. Group 2: 26.0%; p = 0.030) and histologic grade 3 (Group 1; 41.67% vs. Group 2: 67.73%; p = 0.032). Subgroup analyses showed significant difference (p < 0.05) for more advanced cancers (larger tumor, node positive, metastatic disease, poorly differentiated cancer).

CONCLUSIONS

In this study of patients with the same ethnicity, the better survival outcome in latter (Group 2) patients suggests improvement of treatment, especially for patients with more advanced and metastatic cancer (stage IV).

The postoperative recurrence and the occurrence of second primary carcinomas in patients with early gastric carcinoma

OBJECTIVE

Early gastric cancers have recently become more prevalent, and therefore, characterization of the features of patients who develop recurrence and second cancers is necessary for the development of effective postoperative follow-up strategies.

METHODS

We evaluated the clinicopathological features and the timing of the development of both recurrence and second primary cancer after surgery for early gastric cancer in 671 patients.

RESULTS

The incidence rate of recurrent early gastric cancer was 2.1%, and the incidence rate of second primary cancer was 4.8%, with an associated death rate of 3.3%. Most multiple primary cancers cases involved the colorectum and the lung. A multivariate analysis of overall survival identified multiple primary cancers, age, and sex as prognostic factors for early gastric cancer. The average interval from surgery to diagnosis of recurrence was identified as 3.4 +/- 2.1 years. The average interval for peritoneal recurrence was shorter than that for hematogenous recurrence (P < 0.05). The average interval from diagnosis of early gastric cancer to diagnosis of the second primary cancer was 7.1 +/- 4.6 years.

CONCLUSION

Patients with early gastric cancer, particularly patients who are males, elderly and have lymphatic involvement, tend to have a greater risk of developing a second primary cancer and recurrence, respectively.

Gastrectomy for patients with gastric cancer and non-uremic renal failure

AIM: To investigate the safety and outcome of gastrectomy for patients with gastric cancer and non-uremic renal failure (NURF).

METHODS: One hundred forty-seven patients who underwent gastrectomy for carcinoma were retrospectively divided into two groups: a group with Ccr values of ≥ 50 mL/min (Group 1; n = 110), and one with Ccr values of ≥ 20 to < 50 mL/min (Group 2; n = 37). Preoperative patient characteristics, intraoperative parameters (including operation time and blood loss), and postoperative management and complications were evaluated.

RESULTS: There were no statistically significant differences between the two groups in operation time (297.9 min vs 272.6 min, P = 0.137) or blood loss (435 mL vs 428 mL, P = 0.078). The differences in postoperative complications and hospital stay between the groups were not statistically significant. None of the patients in Group 2 required dialysis therapy, and no patients died due to gastrectomy or gastrectomy-related causes. The overall 4-year survival rates in Groups 1 and 2 were 86.6% and 81.8%, respectively (P = 0.48), and the corresponding 4-year disease-free survival rates for stageI, II, and III patients were 88.7% and 83.5%, respectively (P = 0.65).

CONCLUSION: Gastrectomy can be performed as safely in patients with NURF similar to patients with normal renal function.

Hereditary factors in multiple primary malignancies associated with lung cancer

PURPOSE

There are differences between lung cancer alone and multiple primary malignancies associated with lung cancer (MPMLC) in terms of clinical characteristics. However, the importance of these differences has not yet been clarified.

METHODS

Univariate and multivariate analyses were performed on 123 patients with MPMLC and 815 patients with lung cancer alone who underwent operative procedures for lung cancer from August 1982 to March 2004.

RESULTS

Age, number of family with a family history of other malignancies except for smoking-related cancers, and pathological early stage of lung cancer were significantly high in patients with MPMLC based on univariate analyses (P < 0.0001, P < 0.05, and P < 0.05, respectively). Age and family history of malignancy were thus found to be significant factors based on a multivariate analysis.

CONCLUSIONS

MPMLC demonstrated a significant association with advanced age and stronger hereditary factors in comparison with lung cancer alone, indicating the need for different approaches to properly manage and follow up risk patients.

Analysis of non-genetic risk factors for adverse skin reactions to radiotherapy among 284 Breast Cancer patients

OBJECTIVES

We analyzed non-genetic risk factors for adverse skin reactions to irradiation at 4 collaborating Japanese institutions, to design future investigation into genetic risk factors for adverse skin reactions to irradiation in a multicenter setting.

METHODS

From April 2001, 284 breast cancer patients, who underwent radiotherapy with breast-conserving surgery, were enrolled from 4 collaborating institutions in Japan. We graded skin reactions according to international scoring systems. Clinical factors were tested against adverse effects.

RESULTS

Grade 1+ skin reactions were observed in 261 (92%) of the patients in less than 3 months, 118 (42%) at 3 months, and 29 (10%) at 6 months in the late phase. Univariate analysis of treatment risk factors (such as the use of a multi-leaf colimeter, wedge-filter, or immobilization device) for skin reactions revealed a significant association (p< 0.0001). After a variable selection procedure with logistic regression, the institution, operative procedure, and magnitude of photon energy remained significantly associated with acute skin reactions. Only the institution was an explanatory variable for skin reactions at 3 and 6 months in the final logistic model.

CONCLUSION

After stratification, substantial remaining variations in the occurrence of skin reactions of a given level suggested that individual genetic factors contribute markedly to individual radiosensitivity. Analysis of genetic factors associated with adverse effects would be possible by stratifying patients according to institution. Selection of eligible institutions, where appropriate treatment modalities could be performed, would also be possible when planning such a study.

Characteristics of Multiple Primary Malignancies Associated with Lung Cancer by Gender

BACKGROUND

There are gender differences in multiple primary malignancies associated with lung cancer (MPMLC) in terms of clinical characteristics. However, the importance of these differences in the management of patients has not been clarified.

OBJECTIVE

Differences in characteristics affected by gender were investigated in MPMLC to identify factors important for the proper management of the patients.

METHODS

Univariate and multivariate analyses were performed between 82 male and 34 female patients with MPMLC treated from August 1982 to March 2002.

RESULTS

In univariate analysis, the numbers of smokers or ex-smokers, smoking-related cancer and synchronous multiple primary malignancies were significantly increased in males with MPMLC (p < 0.0001, p < 0.05 and p < 0.05, respectively). In multivariate analysis, synchronous multiple primary malignancies and the number of smokers or ex-smokers were significantly different between male and female MPMLC. Gastric, lung and colon cancers were major constituents in male MPMLC, and 40.2% of all malignancies were smoking-related cancers. On the other hand, breast and uterine cancers were major constituents in female MPMLC, and only 20.6% of all MPMLC were smoking-related cancers.

CONCLUSIONS

Male patients with MPMLC demonstrated significant smoking history and synchronous multiple primary malignancies, indicating the need for different approaches to properly manage and follow up male versus female MPMLC patients.

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.

The optimal age threshold for screening upper endoscopy for uninvestigated dyspepsia in Taiwan, an area with a higher prevalence of gastric cancer in young adults

BACKGROUND

It is estimated that 1% to 2% of patients with dyspepsia are associated with gastric cancer. To avoid missing gastric cancer, most guidelines recommend that patients over 45 years old should undergo EGD for uninvestigated dyspepsia. In Taiwan, however, the prevalence of gastric cancer in younger patients is higher than that of Western countries. The optimal age threshold for endoscopy in patients with uninvestigated dyspepsia in Taiwan remains controversial. Therefore, we aimed to determine an optimal age threshold for screening endoscopy in patients with uninvestigated dyspepsia to avoid missing gastric cancer in Taiwan.

METHODS

We reviewed the findings in all adult patients who underwent upper endoscopy because of uninvestigated dyspepsia at the National Taiwan University Hospital. In those patients with confirmed gastric cancer histology, further analysis was performed. Cumulative age frequency distributions for gastric cancer were calculated according to gender and to the presence or the absence of alarm features. The stages of gastric cancer also were analyzed according to the presence or the absence of alarm symptoms.

RESULTS

During the 5-year period, a total of 17,894 patients received upper endoscopy caused by uninvestigated dyspepsia. Gastric cancer was found in 225 (12.6 cases per 1000 EGDs) patients who presented with uninvestigated dyspepsia, 135 men and 90 women. Thirty-one (13.7%) and 17 (7.6%) patients were aged less than 45 and 40 years old, respectively. Among these 225 patients with gastric cancer, 114 (50.7%) patients did not have alarm symptoms (simple dyspepsia), whereas 111 (49.3%) had alarm symptoms. About 5.3% (12/225) of gastric cancer cases would have been missed if endoscopy had been omitted in patients without alarm symptoms and aged less than 45 years. The cumulative age relative frequencies of patients with gastric cancer who presented with simple dyspepsia were 1.8 (12/6720), 1.02 (5/4920), and 0.59 (2/3411) cases per 1000 EGDs for uninvestigated dyspepsia in patients aged less than 45, 40, and 35 years, respectively. When the frequencies of gastric cancer were stratified by age and gender, we found a trend of male predominance in older patients but not in younger patients. The cutoff age was 60 years old ( p < 0.05). Early gastric cancer was detected in 9.9% (11/111) and 26.3% (30/114) of patients with and without alarm symptoms, respectively (p = 0.002).

CONCLUSIONS

Gastric cancer is not uncommon in patients with dyspepsia aged less than 45 years in Taiwan. The age threshold of screening endoscopy for uninvestigated dyspepsia should be the same for both genders in view of comparable frequencies of gastric cancer in a young age population. Because more than 5% of gastric cancer cases would be missed in Taiwan if endoscopy was omitted in simple dyspeptic patients who were aged less than 45 years, we recommend that 40 years old might be an optimal age threshold for screening endoscopy for uninvestigated dyspepsia in Taiwan, in both men and women patients.

Original Article

BACKGROUND

The prolongation of the post-operative life of cancer patients brings new medical demands. The purpose of this paper is to estimate the total number of women patients with breast cancer who will have disability resulting from surgical treatment from 2000 to 2020 in Japan.

METHODS

The estimation was carried out using four indices: the number of cases of women diagnosed with breast cancer, the proportion of surgical operations, the frequency of disability from surgical treatment, and the crude survival rate of the patient group. The crude survival rates of surgically-treated breast cancer patients were estimated by the Weibull model. The frequencies of iatrogenic disabilities were calculated from several reports of complaints of pain in the chest wall or axilla and lymphedema of the arm, and 95% confidence intervals were calculated by the Monte Carlo simulation.

RESULTS AND DISCUSSION

The number of women patients with disability from breast cancer treatment from 2000 to 2020 was estimated to be 42,016 (95% CI: 41,236, 42,796) people in 2000 and 72,514 (95% CI: 71,196, 73,832) people in 2020 for pain in the chest wall or axilla, and 22,486 (95% CI: 22,148, 22,823) people in 2000 and 38,692 (95% CI: 38,094, 39,290) people in 2020 for lymphedema of the arm. Treatment supports required for the disability are medication and social support. Cancer patients with disability after treatment need long-term support in their daily life.

Effective follow-up for recurrence or a second primary cancer in patients with early gastric cancer

BACKGROUND

Patients with early gastric cancer have an excellent prognosis with low rates of recurrence, but may have an increased risk of developing a second primary cancer. Because the number of early gastric cancers has increased, clarification of both recurrences and second primary cancers is important for the development of effective postoperative follow-up programmes.

METHODS

Data on 1070 patients with early gastric cancer were analysed retrospectively with respect to the clinicopathological features of both recurrence and second primary cancers after surgical treatment.

RESULTS

Multivariate analysis showed that lymph node metastasis and older age were independent risk factors for recurrence of early gastric cancer. The incidence of second primary cancers was 5.0 per cent; lung and colorectal cancers were detected most frequently, followed by cancers in the oesophagus, breast and remnant stomach.

CONCLUSION

Clinicopathological features of patients with early gastric cancer can be used to identify those most at risk of developing either recurrence or a second primary cancer.

Frequent downregulation of 14-3-3 sigma protein and hypermethylation of 14-3-3 sigma gene in salivary gland adenoid cystic carcinoma

14-3-3 sigma:, a target gene of the p53 tumour suppressor protein, has been shown to regulate the cell cycle at the G2/M checkpoint. Recent studies have demonstrated that 14-3-3 sigma is downregulated by hypermethylation of the CpG island in several types of cancer. In this study, we investigated the expression and methylation status of 14-3-3 sigma in human salivary gland adenoid cystic carcinoma (ACC) and mucoepidermoid carcinoma (MEC). Immunohistochemical analysis revealed that the positive expression rate of 14-3-3 sigma in ACC (one out of 14) was markedly lower than that in MEC (ten out of 10). Since most of the ACCs carried the wild-type p53 protein, downregulation of 14-3-3 sigma in ACC may not be due to the dysfunction of p53 pathway. Microdissection-methylation-specific PCR revealed that frequent hypermethylation of the 14-3-3 sigma gene was observed in ACC when compared to that in MEC. In cultured-ACC cells, we confirmed the downregulation of 14-3-3 sigma via hemimethylation of the gene by sequencing analysis after sodium bisulphite treatment. Furthermore, re-expression of 14-3-3 sigma in the ACC cells was induced by the treatment with DNA demethylating agent, 5-aza-2'-deoxycytidine. Irradiation apparently induced the enhanced expression of 14-3-3 sigma and G2/M arrest in normal salivary gland cells; however, in the ACC cells, neither induction of 14-3-3 sigma nor G2/M arrest was induced by irradiation. These results suggest that downregulation of 14-3-3 sigma might play critical roles in the neoplastic development and radiosensitivity of ACC.

A prospective study of diet and prostate cancer in Japanese men

BACKGROUND AND AIMS

It has been hypothesized that some aspect of a traditional 'Asian' diet, that is low in animal products and high in soya, may be associated with a reduced risk of prostate cancer. This study aimed to examine the association between dietary intake and prostate cancer risk among 18,115 men in Hiroshima and Nagasaki, Japan, using prospective data from the Life Span Study.

METHODS

Subjects completed a food-frequency questionnaire at baseline (1963, 1965 and/or 1979) and were followed for incident prostate cancer until the end of 1996. During this time, 196 incident prostate cancer cases were identified after 252,602 person-years of observation. Poisson regression was used to calculate incidence rates for each dietary factor after adjustment for age, calendar period, city of residence, radiation dose and education level.

RESULTS

Fish intake was significantly associated with an increased risk of prostate cancer; men who consumed fish more than four times per week had a 54 increased risk of developing prostate cancer compared with men who ate fish less than twice per week (RR = 1.54; 95% CI, 1.03-2.31). No other food items, including soya products, were significantly associated with prostate cancer risk.

CONCLUSIONS

These data suggest that dietary factors may not be strong determinants of prostate cancer in these Japanese men, although the increased risk associated with a high consumption of fish warrants further study.

Estimation of individualized probabilities of developing breast cancer for Japanese women

BACKGROUND

Projecting individualized probabilities of developing breast cancer is needed for counseling and chemoprevention for Japanese women, in whom breast cancer incidence has been rapidly increasing.

METHODS

We calculated individualized probabilities of developing breast cancer within 10-20 years and until life expectancy for Japanese women by multiplying the relative risk for each risk factor combination by the cumulative risk for the reference group. The risk factors used were age at menarche, age at first delivery, family history of breast cancer, and body mass index (BMI) (in post-menopausal women). The relative risk by menopausal status for each risk factor combination was estimated from a case control study conducted at Osaka Medical Center for Cancer and Cardiovascular Diseases (OMCC), Japan. The cumulative risk of breast cancer for the reference group within 10-20 years and until life expectancy was estimated to divide the corresponding cumulative risk for Japanese women by the weighted average of the relative risk. The weight is an expected proportion of those who have each risk factor combination among the general population. The cumulative risk for Japanese women was estimated using a data file from the Osaka Cancer Registry (OCR).

RESULTS

We obtained cumulative risks for any age women within a certain range according to various risk factor combinations by menopausal state. For example, the highest risk group had about a 5 times higher risk probability of developing breast cancer than the general population at initial age 40, within 10-20 years, and until life expectancy.

CONCLUSION

The cumulative risk of breast cancer varied according to individuals' risk factors among Japanese women. The availability of concrete individualized risk estimation figures will be of use to health care providers in encouraging Japanese women to seek counseling and to adopt self-control of body weight as a primary preventive measure, as well as to have breast cancer screening.

Fish consumption and colorectal cancer: a case-reference study in Japan

Several clinical studies have suggested that supplementation with fish oils can suppress the proliferation of colorectal mucosa and therefore inhibit the development of colorectal cancer. However, epidemiological evidence concerning fish consumption and risk is inconsistent and limited. To clarify the association between intake of fish and the likelihood of developing colorectal cancer, we conducted a large sample size case-reference study with 928 cases of colon cancer, 622 of rectal cancer and 46886 cancer-free outpatient references aged 40-79 years. The data showed frequent raw/cooked fish intake to be associated with decreased odds ratio (OR) 0.68 with 95% confidence interval (CI) 0.47-0.99 for male colon cancer, especially for males aged over 60 years, smokers and frequent meat eaters. A marginal decrease in the OR (OR 0.58, 95% CI 0.31-1.07) was also detected for female rectal cancer, especially in the regular physical exercise subgroup. However, frequent dried/salted fish intake was found to be associated with increased OR in females younger than 60 years old and alcohol drinkers. Although there is some possible bias in epidemiological studies, the results suggest that frequent raw/cooked fish intake may decrease the risk while dried/salted fish, in contrast, may exert a detrimental effect.

Height, weight, menstrual and reproductive factors and risk of gastric cancer among Japanese postmenopausal women: analysis by subsite and histologic subtype

To clarify whether reproductive factors have an impact on gastric cancer in Japanese females, a case-control study was conducted using data from the Hospital-based Epidemiologic Research Program at Aichi Cancer Center (HERPACC), Japan. The study subjects included 365 postmenopausal women with gastric cancer and 1,825 age-class frequency-matched noncancer outpatients presenting at Aichi Cancer Center in 1988-1998. Cases were further divided with regard to the anatomic subsite (upper third, middle third, lower third) and histologic subtypes (differentiated, nondifferentiated) and the association was evaluated using odds ratios (ORs) estimated by the logistic regression model, adjusting for potential confounding factors. A high body weight and corresponding body mass index at age 20 moderately increased the risk of gastric cancer, especially for middle third and nondifferentiated cancers. Risk fluctuation with early or late age at menarche and menopause and total duration of fertility was not consistent. Individuals with a high age at first parity tended to show decreased risk of cancer, irrespective of their subsite or histologic subtype. The ORs were decreased with a short average period of breastfeeding, especially for upper third and nondifferentiated cancers. From these results, however, it appears that height, weight, menstrual and reproductive factors have less impact on gastric cancer than environmental factors such as smoking and dietary habits or family history of gastric cancer.