1. Epidemiology: Leading Cancers Worldwide Worldwide, 8.1 million new cancer cases were estimated for 1990, the most recent year for which complete global data are available. The ranking of the 10 most common sites for new cancers among men and women are shown in this slide. The four most common sites in both sexes combined were lung, stomach, breast, and colon and rectum, each representing more than 750,000 cases.
2. Epidemiology: Cancer Incidence by World Region The incidence of cancers is known to vary substantially from one world region to another. North America and Australia/New Zealand, for example, have incidences of cancers among both males and females that are considerably higher than in other developed regions. In contrast, Northern and Western Africa and many parts of Asia have the lowest cancer incidences.
3. Epidemiology: Leading Causes of Death In one developed country, the United States, for which complete epidemiologic data are available, cancer is second only to heart disease as the leading cause of death. Cancer deaths account for slightly less than one-quarter of all deaths in the United States, substantially ahead of other common causes of death.
4. Epidemiology: Evolution of Cancer Death Rates, Males Cancer death rates in one developed country, the United States, have shown dramatic changes over the past several decades. Age-adjusted death rates due to cancers of the lung and bronchus, for example, nearly doubled from 1960 through 1996, before declining thereafter. In contrast, death rates due to stomach cancer declined markedly over this time.
5. Epidemiology: Evolution of Cancer Death Rates, Females The most marked changes in cancer death rates among women in one developed country, the United States, over the past several decades were observed in cancers of the lung and bronchus, stomach, uterus, and colon and rectum. Whereas age-adjusted death rates due to lung cancer more than tripled among women from 1960 through 1996, deaths due to cancers of the stomach, uterus, and colon and rectum have declined steadily.
6. Epidemiology: Mortality for Leading Cancers (Males) Mortality due to different cancer types among males is known to vary by age. Cancers of the lung and bronchus, which are the most common cause of cancer death among males in the United States, are relatively uncommon among men 20 to 39 years of age, but are the most common cause of cancer death among men 40 to 59 and 60 to 79 years of age. Similarly, prostate cancer is uncommon in younger men, but emerges as the second most common cause of cancer death among men 60 to 79 years of age and men over the age of 80.
7. Epidemiology: Mortality for Leading Cancers (Females) Cancer mortality among women is known to vary by age for different cancer types. Breast cancer is the most common cause of cancer mortality among women 20 to 39 and 40 to 59 years of age. However, cancers of the lung and bronchus are the most common causes of cancer deaths in women 60 to 79 years of age and in women over the age of 80.
8. Epidemiology: Male Cancer Statistics The estimated incidence of various cancer types and number of cancer deaths due to these cancers among men in the United States are shown in this table. Whereas, prostate cancer is the most common cancer type among males, representing 29% of all cancers, cancers of the lung and bronchus are the most common causes of cancer deaths among men, accounting for 31% of all cancer deaths.
9. Epidemiology: Female Cancer Statistics The estimated incidence of various cancer types and the estimated number of cancer deaths due to these cancers among women in the United States are shown in this slide. Breast cancer, which accounts for 30% of all cancers in these women, is implicated in 15% of cancer deaths. In contrast, cancers of the lung and bronchus account for 12% of cancers but are implicated in 25% of cancer deaths.
10. Epidemiology: Known Cancer Causes A number of exogenous factors are well known to cause cancer in exposed persons. Much has been written about occupational exposure to a broad array of carcinogens, such as benzene, asbestos, and polychlorinated biphenyls though such exposure has been considerably reduced in developed regions of the world. Lifestyle choices such as diet, consumption of tobacco and/or alcohol, and exposure to biologic agents, such as the hepatitis B or C viruses or the Epstein-Barr virus, have also been demonstrated to lead to the development of cancer. Iatrogenic factors, such as the use of some pharmaceutical agents or ionizing radiation, may also contribute to the development of some cancers.
11. Epidemiology: Alcohol-Related Cancers Alcoholic beverages have been judged by IARC (WHO) as a lifestyle factor linked to cancer in the esophagus, oral cavity, pharynx, larynx, and liver. High intakes of alcohol in combination with low intakes of methionine and folate have been associated with a substantially increased risk for colon cancer. While some studies have found an association between alcohol and pancreatic cancer, results of several epidemiologic studies have refuted these findings. Alcohol is also considered a risk factor for breast cancer, but studies have not yet conclusively demonstrated a plausible mechanistic process between alcohol consumption and breast cancer.
12. Epidemiology: Smoking-Related Cancers Overall, cigarette smoking has been identified as the chief preventable cause of deaths due to cancer in the United States. It is a major cause of cancers of lung, larynx, oral cavity, and esophagus, and a contributory factor in pancreatic, bladder, kidney, stomach, and uterine cervix cancers.
13. Epidemiology: Virus-Related Cancers Overwhelming evidence shows that chronic infection with hepatitis B is an important cause of hepatocellular carcinoma (HCC)—the most common primary liver cancer. Epidemiologic studies have shown hepatitis C to also be conclusively linked to HCC, while HTLV-1 appears to cause adult T-cell leukemia or lymphoma. HPV is likely to be an important determinant of cervical cancer, and strong evidence also indicates that Epstein-Barr virus is a causal factor of Burkitts’ lymphoma, cancer of the nasopharynx, and Hodgkin’s disease.
14. Epidemiology: Bacterial-Related Cancers In Asia, a more rare histologic type of liver cancer, cholangiocarcinoma, has been linked to infestation by Opisthorchis viverrini. Other studies have suggested that gastric infection with the bacterium Helicobacter pylori is an important risk factor for gastric cancer. In parts of Africa and the Middle East, infection with the bladder parasite Schistosoma haematobium plays a major role in the causation of bladder cancer.
15. Epidemiology: Iatrogenic Contributors The relation between ionizing radiation and breast cancer is well established, with preadolescent exposure greatly increasing the risk of radiation-induced breast cancer. Low doses of ionizing radiation may cause childhood leukemia, and high doses have consistently been found to be leukemogenic.
16. Epidemiology: Iatrogenic Contributors (cont’d) A number of pharmaceutical agents have been determined to be human carcinogens. Cancer chemotherapeutic drugs have been linked to bone marrow cancer, while immunosuppressive drugs have been shown to have a carcinogenic effect on the reticuloendothelial system. Estrogen replacement is known to elevate the risk for both breast and endometrial cancer, while tamoxifen increases the risk for endometrial cancer. Diethylstilbestrol has demonstrated a causal relationship to cancers of the vagina and cervix uteri. Increased risk for liver cancer was found among anabolic steroid and oral contraceptive users. Finally, phenacetin analgesics are implicated in the cause of kidney and pelvis cancer.
17. Epidemiology: Occupational-Related Cancers The American Cancer Society estimates that approximately 20,000 deaths in the United States can be attributed to occupational exposure to carcinogens. This slide lists occupational cancers by industry and carcinogen.
18. Epidemiology: Genetic Risk Factors: Mechanisms of Cancer Predisposition Several mechanisms have been proposed to explain the genetic basis of cancer. An individual’s predisposition can be attributed to germline mutations that inactivate tumor-suppressor genes that would normally serve to inhibit inappropriate and unregulated cell growth and proliferation. Conversely, mutations that produce inappropriate activation of germline oncogenes can stimulate DNA synthesis, cell growth and division. Defects in DNA repair mechanisms can increase the risk that mutations in cancer-related genes will lead to cancerous disease. Ecogenetic traits are believed to reflect individuals’ increased susceptibility to common carcinogens due to polymorphisms in systems affected by or involved in the clearance of exogenous carcinogens from the body.
19. Epidemiology: Genetic Risk Factors: Characteristics of Cancer Families Expression of hereditary cancers may be observed in at least some members of families that have a history of cancer. Cancers in individuals within these families often manifest relatively early in life, possibly in the form of birth defects, and may appear as multiple and bilateral tumors. Hereditary cancers may include rare tumor types, such as retinoblastoma or breast cancer in males, may affect multiple body systems, and may be revealed with variable expressivity among members of the family.
20. Epidemiology: Genetic Risk Factors: Familial Cancer Syndromes A number of familial cancer syndromes have been identified. These typically rare syndromes include neurofibromatosis Types 1 and 2, von Hippel-Lindau disease, hereditary Wilms’ tumor and related syndromes, Li-Fraumeni syndrome, and nevoid basal cell carcinoma syndrome.
21. Epidemiology: Genetic Risk Factors: Familial Cancer Syndromes (cont’d) Other familial cancer syndromes include familial adenomatous polyposis, hereditary nonpolyposis colorectal cancer, Cowden’s syndrome, and cancers associated with the presence of the BRCA-1 and BRCA-2 genes.
22. Epidemiology: Reducing Mortality An estimated one in three Americans will have cancer over the course of his or her lifetime. However, the National Cancer Institute suggests that a substantial reduction in cancer mortality could be achieved through the following measures: control of tobacco use, widespread adoption of a low-fat diet with greatly increased fiber consumption, early detection and screening, and the wider application of state-of-the art treatments.
23. Epidemiology: Risk Reduction The elimination of exposure to risk factors is the focus of cancer primary prevention efforts. The relative risk for a particular type of cancer describes the greater risk of the population exposed to the risk factor compared to those not exposed. For example, the relative risk of developing lung cancer is 11 for smokers, meaning that the relative risk is 11 times greater for smokers than nonsmokers. The population attributable risk describes the percentage of cancer cases that could be eliminated by eliminating exposure to the risk factor. For example, it is estimated that 87% of the lung cancer cases could be eliminated by eliminating exposure to smoking.
24. Epidemiology: Modifiable Risk Factors This slide lists the modifiable risk factors for lung and colorectal cancers, along with the magnitude of the relative risk and the best available estimate of attributable risk for these cancers.
25. Epidemiology: Modifiable Risk Factors (cont’d) This slide lists the modifiable risk factors for breast cancer, along with the magnitude of the relative risk and the best available estimate of attributable risk for this cancer.
26. Epidemiology: Modifiable Risk Factors (cont’d) This slide lists the modifiable risk factors for cancer of the cervix, along with the magnitude of the relative risk and the best available estimate of attributable risk for this cancer.
27. Epidemiology: Early Detection Guidelines This slide lists the American Cancer Society’s guidelines for early detection of a variety of cancers in both men and women.
ONCOLOGY Epidemiology 1 Lung Breast Lung 1,037,000 2 Stomach Colon/rectum Stomach 798,000 3 Colon/rectum Cervix uteri Breast 796,000 4 Prostate Stomach Colon/rectum 783,000 5 Liver Lung Liver 437,000 6 Mouth/pharynx Ovary Prostate 396,000 7 Esophagus Corpus uteri Cervix uteri 371,000 8 Bladder Liver Mouth/pharynx 363,000 9 Leukemia Mouth/pharynx Esophagus 316,000 10 NHL* Esophagus Bladder 261,000 Total New Rank Males Females Both Sexes Cases *Non-Hodgkin’s lymphoma. Adapted from Parkin DM, et al. CA Cancer J Clin. 1999;49:39. Leading cancers worldwide
ONCOLOGY Epidemiology 1 N. America 369.9 N. America 277.5 2 Australia/N.Z. 312.7 Australia/N.Z. 254.0 3 W. Europe 294.8 N. Europe 234.5 4 Japan 270.9 S. America* 230.1 5 N. Europe 270.0 W. Europe 210.4 6 E. Europe 269.4 Micronesia/ 205.2 Polynesia 7 S. Europe 256.0 Southern Africa 187.8 8 S. America* 255.1 Melanesia 185.6 9 Southern Africa 247.4 S. America † 185.0 10 Eastern Asia ‡ 235.7 Central America 180.1 Incidence/ Incidence/ Rank Region 100,000 Region 100,000 *Temperate South America. † Tropical South America. ‡ Other than Japan or China. Adapted from Parkin DM, et al. CA Cancer J Clin. 1999;49:43. Cancer incidence by world region Males Females
ONCOLOGY Epidemiology Adapted from Greenlee RT, et al. CA Cancer J Clin. 2000:50;22. Leading causes of death Percentage of Total Deaths, US Heart Diseases Cancer Cerebrovascular Diseases Chronic Obstructive Lung Diseases Accidents Pneumonia & Influenza Diabetes Mellitus Suicide Homicide HIV Infection
ONCOLOGY Epidemiology Adapted from Greenlee RT, et al. CA Cancer J Clin. 2000;50:27. Evolution of cancer death rates, males Pancreas Liver Prostate Stomach Lung & bronchus Colon & rectum Leukemia 10 20 30 40 50 60 70 Rate per 100,000 Male Population Year 1930 1940 1950 1960 1970 1980 1990
ONCOLOGY Epidemiology Rate per 100,000 Female Population Year Adapted from Greenlee RT, et al. CA Cancer J Clin. 2000;50:26. Evolution of cancer death rates, females 0 40 10 20 30 Uterus † Breast Pancreas Ovary Stomach Lung & bronchus Colon & rectum 1930 1940 1950 1960 1970 1980 1990
ONCOLOGY Epidemiology *Non-Hodgkin’s lymphoma. † Other nervous system. Mortality for leading cancers Adapted from Greenlee RT, et al. CA Cancer J Clin. 2000;50:23. Males by Age (years), US All Ages Lung & bronchus 91,278 Prostate 32,891 Colon & rectum 28,075 Pancreas 13,470 NHL 12,286 20-39 NHL* 723 Leukemia 662 Brain & ONS † 625 Lung & bronchus 512 Colon & rectum 412 60-79 Lung & bronchus 59,558 Prostate 16,277 Colon & rectum 15,842 Pancreas 7,898 NHL 6,383 > 80 Lung & bronchus 15,823 Prostate 15,511 Colon & rectum 7,459 Bladder 2,900 Pancreas 2,843 40-59 Lung & bronchus 15,379 Colon & rectum 4,347 NHL 2,552 Pancreas 2,584 Esophagus 2,069
ONCOLOGY Epidemiology *Other nervous system. † Non-Hodgkin’s lymphoma. Mortality for leading cancers Adapted from Greenlee RT, et al. CA Cancer J Clin. 2000;50:23. All Ages Lung & bronchus 61,922 Breast 41,943 Colon & rectum 28,621 Pancreas 14,205 Ovary 13,507 20-39 Breast 1,629 Uterine cervix 629 Leukemia 462 Lung & bronchus 462 Brain & ONS* 385 60-79 Lung & bronchus 38,488 Breast 18,385 Colon & rectum 12,799 Pancreas 7,437 Ovary 7,207 > 80 Lung & bronchus 12,879 Colon & rectum 12,046 Breast 9,835 Pancreas 5,045 NHL † 3,859 40-59 Breast 12,093 Lung & bronchus 10,088 Colon & rectum 3,426 Ovary 2,801 Uterine cervix 1,803 Females by Age (years), US
ONCOLOGY Epidemiology Male cancer statistics Adapted from Greenlee RT, et al. CA Cancer J Clin. 2000;50:16. Estimated incidence Estimated deaths Melanoma of skin Oral cavity & pharynx Lung & bronchus Pancreas Kidney & renal pelvis Colon & rectum Prostate Urinary bladder Leukemia Non-Hodgkin’s lymphoma All others 4% 3% 14% 2% 3% 10% 29% 6% 3% 5% 19% Esophagus Lung & bronchus Pancreas Liver & intrahepatic bile duct Stomach Colon & rectum Prostate Urinary bladder Leukemia Non-Hodgkin’s lymphoma All others 3% 31% 5% 3% 3% 10% 11% 3% 4% 5% 22%
ONCOLOGY Epidemiology Female cancer statistics Adapted from Greenlee RT, et al. CA Cancer J Clin. 2000;50:16. 2% 15% 25% 5% 2% 11% 5% 2% 5% 4% 2% 21% Melanoma of skin Thyroid Breast Lung & bronchus Pancreas Colon & rectum Ovary Uterine corpus Urinary bladder Non-Hodgkin’s lymphoma All others 3% 2% 30% 12% 2% 11% 4% 6% 2% 4% 22% Brain & other nervous system Breast Lung & bronchus Pancreas Stomach Colon & rectum Ovary Uterine corpus Non-Hodgkin’s lymphoma Leukemia Multiple myeloma All others Estimated incidence Estimated deaths
Virus-related cancers Adapted from Trichopoulos D, et al. Cancer: Principles & Practice of Oncology. 5th ed. 1997;249. Site of Cancer Liver Liver Adult T-cell leukemia or lymphoma Uterine cervix Burkitt’s lymphoma, nasopharynx, Hodgkin’s disease
Neurofibromatosis type 1 CNS, neurofibrosarcomas, pheochromocytomas, leukemia
Neurofibromatosis type 2 CNS, spine von Hippel-Lindau disease CNS, renal cell, spine, pancreas, adrenal glands
Li-Fraumeni syndrome CNS, breast, head and neck, soft tissue, osteosarcoma, adrenal cortical carcinomas, leukemia
Wilms’ tumor gene Wilms’ tumor
Basal cell carcinoma syndrome Skin, CNS, ovary
Genetic risk factors: Familial cancer syndromes Bale AE, Li FP. Cancer: Principles & Practice of Oncology . 5th ed. 1997;285-293. Linehan WM, et al. Cancer: Principles & Practice of Oncology . 5th ed. 1997;1253-1271.
8% to 16% by a 15% decrease in tobacco use among adults
8% by dietary measures (ie, reduction of dietary fat to <25% and double dietary fiber)
3% by early screening and early detection
10% to 26% by the wider application of state-of-the art treatments
Reducing mortality Bal DG, et al. American Cancer Society Textbook of Clinical Oncology . 2nd ed. 1995;40-63. The National Cancer Institute estimates that cancer mortality rates could be significantly reduced, as follows:
Sigmoidoscopy, preferably flexible M&F > 50 Every 3-5 yrs, based on advice of physician
Fecal occult blood test M&F > 50 Every year
Digital rectal exam M&F > 40 Every year
Prostate exam M > 50 Every year
Pap test F > 18* Every year, if normal >3 times, Pap test may be performed less frequently at discretion of physician
Pelvic exam F 18-40 Every 1-3 years, with Pap test
>40 Every year
Endometrial tissue sample F † At menopause and thereafter at discretion of physician
Breast self-exam F > 20 Every month
Breast clinical exam F 20-40 Every 3 years >40 Every year
Mammography F 40-49 Every 1-2 years (1st by age 40) >50 Every year
Health counseling and cancer M&F >20 Every 3 years checkups >40 Every year
Early detection guidelines Adapted from Fink DJ, Mettlin CJ. American Cancer Society Textbook of Clinical Oncology . 2nd ed. 1995;181. ACS Screening Recommendations for Asymptomatic People (Average Risk) * Or before if sexually active. † At menopause, for women at high risk for endometrial cancer due to history of infertility, obesity, failure to ovulate, abnormal uterine bleeding, unopposed ERT or tamoxifen use.