Cancer Care

Cancer rates vary with age, acculturation and location. Some of these differences may represent the influence of environment, such as diet and health habits, and therefore may be modifiable. (National Cancer Institute Registry: http://seer.cancer.gov/) Concomitantly, genetics may play a role as well. There is wide inter-individual variability in the pharmacokinetics, pharmacodynamics and tolerance of anticancer drugs. Recent evidence suggests that there is even greater variability between individuals of different ethnicity. Allelic variants of genes encoding drug metabolising enzymes are expressed with different incidences in different ethnic groups, particularly between Asian and Caucasians, and some of these variants result in altered enzyme function. There is also preliminary evidence to suggest that ethnic differences in the expression of allelic variants may produce altered pharmacokinetics of anticancer drugs, including paclitaxel and irinotecan. Emerging evidence indicates that toxicity from certain anticancer treatments is much greater in Asian patients than Caucasians in breast and lung cancers. Understanding the causes of ethnic differences in cytotoxic metabolism may promote improved and more individualised prescribing, as well as culturally competent prescribing. (Phan 2009)

Liver Cancer

Asian Americans have the highest rate of liver cancer as well as mortality from liver cancer among all U.S. ethnic and racial populations. The incidence rate for liver and intrahepatic bile duct cancer among Asian/Pacific Islanders (from 2002 to 2006) was 21.4 per 100,000 men and 8.3 per 100,000 women.

Mortality rates among Asian/Pacific Islanders were 15.0 per 100,000 men and 6.6 per 100,000 women. Both incidence and mortality rates were higher compared with White or Black populations in the U.S. (http://seer.cancer.gov/statfacts/html/livibd.html)

This is the most significant cancer health disparity affecting Asian Americans in the U.S. On the positive side, Asians/Pacific Islanders have experienced a significant decrease in mortality rates over time compared to other groups. (Altekruse, 2009; Wong 2009) Specific data for liver cancer in Chinese-Americans were hard to obtain.

Nasopharyngeal Cancer (NPC)

Chinese-Americans have the highest rates in the U.S. Rates vary among Chinese living in mainland China, the U.S., Hong Kong and Singapore.

Despite having higher incidence rates of NPC and the same risks of NPC-related mortality compared with other groups, Chinese NPC patients in the US have better overall survival. (Sun et al, 2007)

Breast Cancer

The incidence rate for breast cancer among Asian/Pacific Islander women (from 2002 to 2006) was 89.5 per 100,000 women. Mortality rates among Asian/Pacific Islander women were 12.5 per 100,000 women. Both incidence and mortality rates were lower compared with White or Black populations in the U.S. (http://seer.cancer.gov/statfacts/html/breast.html)

The risk of breast cancer is higher in Chinese-American immigrants than in Chinese living in Asia. Breast cancer is the most commonly diagnosed cancer in Chinese females living in the US. Factors such as the use of estrogens, nulliparity, fewer births, older age of first birth and obesity may be responsible for rate differences in various countries. A retrospective study of 499 ethnically diverse women with breast cancer found that in the Asian group, 96% of breast cancer patients who were either nulliparous or had late onset of first childbirth were found to have estrogen positive disease, whereas only 52% of those without these risk factors were found to be estrogen positive. (Menes et al, 2007) These differences were not found among the White, Hispanic or African American women. Chinese women are less likely to receive mammograms than white women. Some barriers may include lack of knowledge, lack of insurance coverage, as well as lack of access. (Lee-Lin et al, 2007)

Prostate Cancer

The incidence rate for prostate cancer among Asian/Pacific Islander men (from 2002 to 2006) was 91.1 per 100,000 men. Mortality rates among Asian/Pacific Islander men were 10.6 per 100,000 men. Both incidence and mortality rates were lower compared with White or Black populations in the U.S. (http://seer.cancer.gov/statfacts/html/prost.html)

The rate of prostate cancer increases sharply with age, and the rate of prostate cancer among Chinese-American men is three to five times higher than Chinese living in Asia. Robbins et al. (2007) conducted a study of prognostic factors and survival from prostate cancer in non-Hispanic whites and 6 Asian subgroups (Chinese, Filipino, Japanese, Korean, South Asian, and Vietnamese), using data from all men in California diagnosed with incident prostate cancer during 1995-2004 and followed through 2004 (n = 116,916). On multivariate analyses adjusting for all prognostic factors, all subgroups except South Asian,and Vietnamese men had significantly better survival than whites; the latter 2 groups had statistically equal survival. This study showed that Chinese American men had better survival rates compared with White men, but the reasons were unclear. Another study among Medicare recipients investigated differences in disease-free survival among white, black, Hispanic, and Asian patients in a large, population-based database. It found that the disease-free survival of white, Hispanic, and Asian patients were not statistically different. (Cohen et al, 2006)

Colon Cancer.

The incidence rate for colon and rectal cancer among Asian/Pacific Islanders (from 2002 to 2006) was 46.9 per 100,000 men and 34.6 per 100,000 women. (http://seer.cancer.gov/statfacts/html/colorect.html). Mortality rates among Asian/Pacific Islanders were 13.8 per 100,000 men and 10.0 per 100,000 women. Both incidence and mortality rates were lower compared with White or Black populations in the U.S.

Among Chinese living in various countries, the variable rates suggest diet related and other environmental risk factors for colon cancer. The rates are higher among U.S. and Hong Kong Chinese than in mainland China. There are no specific and time-correlated studies of cancer incidence across various Chinese subgroups. But Cao et al (2009) reported data on colorectal cancer patients during 2000-2002 that were collected from Guangzhou’s population-based cancer registry. They found the crude incidence of colon cancer to be 13.4 per 100,000 (13.5 per 100,000 in males, 13.3 per 100,000 in females), and the crude incidence of rectal cancer to be 9.6 per 100,000 (10.8 per 100,000 in males, 8.2 per 100,000 in females). In terms of mortality of colon cancer, the rate was 7.1 per 100,000 (7.3 per 100,000 in males, 6.9 per 100,000 in females). The mortality rate for rectal cancer was 5.0 per 100,000 (5.5 per 100,000 in males, 4.5 per 100,000 in females).

Chiu et al. (2005) conducted a study in Taiwan, to determine the frequency of colorectal neoplasia in an asymptomatic Taiwanese population and the topographic distribution of lesions relative to age and gender. Of 1741 (94.3%) patients (1041 men, 700 women; mean 52.5 years) enrolled, 1708 (98.1%) underwent total colonoscopy. The authors found that 263 (15.4%) had colorectal neoplasia and 51 (3.0%) had advanced lesions.

In terms of risk factors, Murphy et al (2009) examined the association of family history of cancer and subsequent colorectal cancer risk in a cohort of traditionally low-risk Chinese women. They followed 73,358 women in the Shanghai Women’s Health Study for cancer incidence. After an average of 7 years of follow-up, 391 women were diagnosed with colorectal cancer. They adjusted the data for age, smoking, family income, education, body mass index, physical activity, and history of diabetes. The authors found a significant association between colorectal cancer risk and history of a parent being diagnosed with colorectal cancer (hazard ratio: 3.34; 95% confidence interval: 1.58, 7.06). No association was observed for colorectal cancer diagnosed among siblings. Also, colorectal cancer risk was not influenced by a positive family history of cancer generally or any of the other cancers investigated (lung, breast, prostate, gastric, esophageal, endometrial, ovarian, urinary tract, central nervous system, and small bowel). These cohort results suggest that consistent with findings from Western populations, having a family history of colorectal cancer may influence colorectal cancer risk to a similar extent in a low-risk population.

Lung Cancer

The incidence rate for lung and bronchus cancer among Asian/Pacific Islanders (from 2002 to 2006) was 53.4 per 100,000 men and 28.1 per 100,000 women. (http://seer.cancer.gov/statfacts/html/lungb.html) Mortality rates among Asian/Pacific Islanders were 36.9 per 100,000 men and 18.2 per 100,000 women. Both incidence and mortality rates were much higher in males. Both rates were lower in Asians compared with White or Black populations in the U.S.

Lung cancer rates vary widely. The highest rates are in Chinese living in Hong Kong (Wang 2009) and Singapore, followed by mainland China, and then the US. Some of the difference in rates probably reflects the rate of smoking in the various areas. However, in many of these areas, women have a low prevalence of smoking. Wang (2009) conducted a population-based case-control study of 212 Hong Kong women diagnosed with primary lung cancer. All cases and controls were life time non-smokers. Results support the etiological link of lung cancer with preexisting lung disease, in particular, asthma, and family cancer history (any cancer).

Lai et al. (2007) describe the experience of dyspnea and helpful interventions in Chinese patients with advanced lung cancer admitted in the palliative care unit in one region in Hong Kong. Eleven participants agreed to be interviewed in this qualitative study, with age ranging from 51 to 80 years. They have been diagnosed with lung cancer from 1 to 12 months, and all required oxygen therapy for dyspnea. Patients in this study found no Chinese words to adequately define and describe dyspnea and relied on sensations they experienced during the dyspnea episode. The impact of dyspnea was multidimensional, and patients used various strategies to manage dyspnea, including avoiding triggers and utilizing traditional Chinese medicine. Overall, healthcare professionals were perceived to play a very inadequate role in assisting patients with dyspnea, and participants suggested that they should take a more active role in educating and supporting patients with dyspnea.