Cancer: Comprehensive guide, origins, therapies, and classifications
More than 40,000 individuals in the U.S. receive a diagnosis of various types of cancer each year, including bladder, colon and rectal, endometrial, kidney, leukemia, liver, melanoma, non-Hodgkin's lymphoma, pancreatic, thyroid, and other forms. In this article, we provide an overview of some of the most prevalent types, their common risk factors, treatments, and prognoses.
Lung cancer, the leading cause of cancer death worldwide, is heavily linked to tobacco smoking. Other risk factors include air pollution, radon, asbestos, and genetic predisposition. Treatment options for lung cancer include surgery, chemotherapy, radiation therapy, immunotherapy, and targeted therapies. The prognosis depends on the stage at diagnosis, with early-stage lung cancer having a better chance of being cured through surgery.
Breast cancer, another common type, is often associated with genetic mutations (BRCA1/2), hormonal factors, alcohol consumption, and obesity. Treatment may involve surgery, chemotherapy, radiation therapy, hormone therapy, targeted therapy (e.g., HER2 inhibitors), and immunotherapy. If detected early, breast cancer generally has a good prognosis.
Colorectal cancer, which includes cancers of the colon, rectum, and appendix, is linked to a diet high in red and processed meats, low physical activity, obesity, smoking, and alcohol consumption. Treatment options include surgery, chemotherapy, radiation therapy, and targeted therapies. Early-stage colorectal cancer has a good prognosis, but the outlook diminishes with advanced disease.
Prostate cancer, more common in men of African descent, is often slow-growing and has an excellent prognosis if detected early. Treatment may involve surgery, radiation therapy, hormone therapy, chemotherapy, and active surveillance.
Stomach (gastric) cancer is often caused by a Helicobacter pylori infection, diet (smoked, salted foods), smoking, and genetic factors. The prognosis is generally poor due to late diagnosis, but early detection significantly improves survival.
Liver cancer is often associated with chronic hepatitis B and C infection, cirrhosis, aflatoxin exposure, and alcohol consumption. Treatment options include surgery, liver transplant, ablation therapies, chemotherapy, and targeted therapies.
Non-Hodgkin lymphoma, a type of cancer that affects the immune system, is linked to immune suppression, certain infections, and chemical exposures. Treatment may involve chemotherapy, radiation therapy, and immunotherapy. The prognosis varies depending on the subtype and stage.
Melanoma, a type of skin cancer, is often linked to ultraviolet radiation, fair skin, and family history. Treatment may involve surgery, immunotherapy, and targeted therapy. Early-stage melanoma has an excellent prognosis, but metastatic melanoma prognosis is poor but improving with immunotherapy.
Environmental and lifestyle factors, such as tobacco smoking, are major risks for multiple cancers, including lung, mouth, throat, esophagus, and pancreas. Infections with certain viruses and bacteria are linked to cancers like cervical, non-Hodgkin lymphoma, liver, and stomach cancers. Genetic factors also play a crucial role in the development of cancer.
Treatments for cancer are typically based on the type of cancer, its stage at diagnosis, and the person's overall health. Common treatment modalities include surgery, chemotherapy, radiation therapy, immunotherapy, targeted therapy, and hormone therapy.
The outlook for a person with cancer depends on whether the disease has spread, its type, severity, and location. Prognosis depends heavily on cancer type, stage at diagnosis, tumor biology, patient's overall health, and treatment response. Early detection generally improves outcomes significantly, with some cancers having high cure rates if detected early (e.g., breast, colorectal, melanoma), while others (e.g., lung, liver) tend to have poorer prognosis due to late diagnosis and aggressive nature.
Continuous research is improving risk prediction, personalized treatment, and survival rates across many cancer types. The American Cancer Society (ACS) reports that the overall cancer death rate has declined by between 1991 and 2020. Improvements in cancer detection, increased awareness of the risks of smoking, and a drop in tobacco use have all contributed to a year-on-year decrease in the number of cancer diagnoses and deaths.
References: [1] National Cancer Institute. (2021). Cancer: What You Need to Know. Retrieved from
- Atopic dermatitis and ulcerative colitis are medical-conditions not directly related to cancer, but their management might benefit from the predictive strategies developed in the science of health-and-wellness.
- In addition to cancer, diabetes is a significant health concern, with lifestyle factors like diet and physical activity playing crucial roles in its prevention and management.
- Psoriasis, a common skin condition, is not considered a cancer, but its treatment might overlap with certain therapies used for cancer, such as immunotherapy.
- While not a cancer, chronic obstructive pulmonary disease (COPD) shares risk factors with lung cancer, such as tobacco smoking, environmental pollutants, and genetic predisposition.
- Cancers like endometrial, kidney, leukemia, pancreatic, thyroid, and other forms, not mentioned extensively in the article, still require ongoing research to improve understanding, treatment, and prognosis.
- Science and medical-research continually strive to improve the understanding of health-and-wellness, encompassing not only cancer but also conditions such as atopic dermatitis, ulcerative colitis, diabetes, psoriasis, and COPD.
- Through various medical-treatments, including surgery, chemotherapy, radiation therapy, immunotherapy, targeted therapy, and hormone therapy, individuals diagnosed with any of the medical-conditions mentioned (atopic dermatitis, ulcerative colitis, diabetes, psoriasis, COPD) can improve their health-and-wellness outcomes.
