Five-year survival rate

Last updated

The five-year survival rate is a type of survival rate for estimating the prognosis of a particular disease, normally calculated from the point of diagnosis. [1] Lead time bias from earlier diagnosis can affect interpretation of the five-year survival rate. [2]

Survival rate is a part of survival analysis. It is the percentage of people in a study or treatment group still alive for a given period of time after diagnosis.It is a method of describing prognosis in certain disease conditions. Survival rate can be used as yardstick for the assessment of standards of therapy. The survival period is usually reckoned from date of diagnosis or start of treatment. Survival rates are important for prognosis, but because the rate is based on the population as a whole, an individual prognosis may be different depending on newer treatments since the last statistical analysis as well as the overall general health of the patient. There are various types of survival rates. They often serve as endpoints of clinical trials and should not be confused with mortality rates, a population metric.

Prognosis is a medical term for predicting the likely or expected development of a disease, including whether the signs and symptoms will improve or worsen or remain stable over time; expectations of quality of life, such as the ability to carry out daily activities; the potential for complications and associated health issues; and the likelihood of survival. A prognosis is made on the basis of the normal course of the diagnosed disease, the individual's physical and mental condition, the available treatments, and additional factors. A complete prognosis includes the expected duration, function, and description of the course of the disease, such as progressive decline, intermittent crisis, or sudden, unpredictable crisis.

Lead time is the length of time between the detection of a disease and its usual clinical presentation and diagnosis. It is the time between early diagnosis with screening and the time in which diagnosis would have been made without screening. It is an important factor when evaluating the effectiveness of a specific test.

Contents

There are absolute and relative survival rates, but the latter are more useful and commonly used.

Relative and absolute rates

Five-year relative survival rates are more commonly cited in cancer statistics. [3] Five-year absolute survival rates may sometimes also be cited. [4]

Relative survival of a disease, in survival analysis, is calculated by dividing the overall survival after diagnosis by the survival as observed in a similar population not diagnosed with that disease. A similar population is composed of individuals with at least age and gender similar to those diagnosed with the disease.

Cancer disease of uncontrolled, unregulated and abnormal cell growth

Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal bleeding, prolonged cough, unexplained weight loss and a change in bowel movements. While these symptoms may indicate cancer, they can also have other causes. Over 100 types of cancers affect humans.

The fact that relative survival rates above 100% were estimated for some groups of patients appears counterintuitive on first view. It is unlikely that occurrence of prostate cancer would increase chances of survival, compared to the general population. A more plausible explanation is that the pattern reflects a selection effect of PSA screening, as screening tests tend to be used less often by socially disadvantaged population groups, who, in general, also have higher mortality. [5]

A counterintuitive proposition is one that does not seem likely to be true when assessed using intuition, common sense, or gut feelings.

Prostate cancer male reproductive cancer

Prostate cancer is the development of cancer in the prostate, a gland in the male reproductive system. Most prostate cancers are slow growing; however, some grow relatively quickly. The cancer cells may spread from the prostate to other areas of the body, particularly the bones and lymph nodes. It may initially cause no symptoms. In later stages, it can lead to difficulty urinating, blood in the urine or pain in the pelvis, back, or when urinating. A disease known as benign prostatic hyperplasia may produce similar symptoms. Other late symptoms may include feeling tired due to low levels of red blood cells.

Selection bias is the bias introduced by the selection of individuals, groups or data for analysis in such a way that proper randomization is not achieved, thereby ensuring that the sample obtained is not representative of the population intended to be analyzed. It is sometimes referred to as the selection effect. The phrase "selection bias" most often refers to the distortion of a statistical analysis, resulting from the method of collecting samples. If the selection bias is not taken into account, then some conclusions of the study may not be accurate.

Uses

Five-year survival rates can be used to compare the effectiveness of treatments. Use of five-year survival statistics is more useful in aggressive diseases that have a shorter life expectancy following diagnosis, such as lung cancer, and less useful in cases with a long life expectancy, such as prostate cancer.

Lung cancer cancer in the lung

Lung cancer, also known as lung carcinoma, is a malignant lung tumor characterized by uncontrolled cell growth in tissues of the lung. This growth can spread beyond the lung by the process of metastasis into nearby tissue or other parts of the body. Most cancers that start in the lung, known as primary lung cancers, are carcinomas. The two main types are small-cell lung carcinoma (SCLC) and non-small-cell lung carcinoma (NSCLC). The most common symptoms are coughing, weight loss, shortness of breath, and chest pains.

Improvements in rates are sometimes attributed to improvements in diagnosis rather than to improvements in prognosis. [6]

To compare treatments independently from diagnostics, it may be better to consider survival from reaching a certain stage of the disease or its treatment.

Analysis performed against the Surveillance, Epidemiology, and End Results database (SEER) facilitates calculation of five-year survival rates. [7] [8]

Related Research Articles

Sarcoma cell type cancer that has material basis in abnormally proliferating cells derived from embryonic mesoderm

A sarcoma is a cancer that arises from transformed cells of mesenchymal origin. Connective tissue is a broad term that includes bone, cartilage, fat, muscle, vascular, or hematopoietic tissues, and sarcomas can arise in any of these types of tissues. As a result, there are many subtypes of sarcoma, which are classified based on the specific tissue and type of cell from which the tumor originates. It is important to note that sarcomas are primary connective tissue tumors, meaning that they arise in connective tissues. This is in contrast to secondary connective tissue tumors, which occur when a cancer from elsewhere in the body spreads to the connective tissue. The word sarcoma is derived from the Greek σάρξ sarx meaning "flesh".

Mesothelioma Cancer associated with asbestos

Mesothelioma is a type of cancer that develops from the thin layer of tissue that covers many of the internal organs. The most common area affected is the lining of the lungs and chest wall. Less commonly the lining of the abdomen and rarely the sac surrounding the heart, or the sac surrounding the testis may be affected. Signs and symptoms of mesothelioma may include shortness of breath due to fluid around the lung, a swollen abdomen, chest wall pain, cough, feeling tired, and weight loss. These symptoms typically come on slowly.

Osteosarcoma bone cancer that is located in bone that has material basis in cells of mesenchymal origin

An osteosarcoma (OS) or osteogenic sarcoma (OGS) is a cancerous tumor in a bone. Specifically, it is an aggressive malignant neoplasm that arises from primitive transformed cells of mesenchymal origin and that exhibits osteoblastic differentiation and produces malignant osteoid.

Oral cancer gastrointestinal system cancer that is located in the oral cavity

Oral cancer, also known as mouth cancer, is cancer of the lining of the lips, mouth, or upper throat. In the mouth, it most commonly starts as a painless white patch, that thickens, develops red patches, an ulcer, and continues to grow. When on the lips, it commonly looks like a persistent crusting ulcer that does not heal, and slowly grows. Other symptoms may include difficult or painful swallowing, new lumps or bumps in the neck, a swelling in the mouth, or a feeling of numbness in the mouth or lips.

Rectal examination Sims position

rectal examination, commonly called a prostate exam, is an internal examination of the rectum, performed by a healthcare provider.

Pagets disease of the breast type of cancer that outwardly may have the appearance of eczema, with skin changes involving the nipple of the breast.

Paget's disease of the breast is a type of cancer that outwardly may have the appearance of eczema, with skin changes involving the nipple of the breast. The condition is an uncommon disease accounting for 1 to 4.3% of all breast cancers and was first described by Sir James Paget in 1874. The condition in itself often appears innocuous, limited to a surface appearance and it is sometimes dismissed, although actually indicative of underlying breast cancer.

Head and neck cancer organ system cancer that arises in the head or neck region (including the nasal cavity, sinuses, lips, mouth, salivary glands, throat, or larynx)

Head and neck cancer is a group of cancers that starts in the mouth, nose, throat, larynx, sinuses, or salivary glands. Symptoms for head and neck cancer may include a lump or sore that does not heal, a sore throat that does not go away, trouble swallowing, or a change in the voice. There may also be unusual bleeding, facial swelling, or trouble breathing.

Screening (medicine) testing a group or population for disease

Screening, in medicine, is a strategy used in a population to identify the possible presence of an as-yet-undiagnosed disease in individuals without signs or symptoms. This can include individuals with pre-symptomatic or unrecognized symptomatic disease. As such, screening tests are somewhat unusual in that they are performed on persons apparently in good health.

Overdiagnosis is the diagnosis of "disease" that will never cause symptoms or death during a patient's ordinarily expected lifetime. Overdiagnosis is a side effect of screening for early forms of disease. Although screening saves lives in some cases, in others it may turn people into patients unnecessarily and may lead to treatments that do no good and perhaps do harm. Given the tremendous variability that is normal in biology, it is inherent that the more one screens, the more incidental findings will generally be found. For a large percentage of them, the most appropriate medical response is to recognize them as something that does not require intervention; but determining which action a particular finding warrants can be very difficult, whether because the differential diagnosis is uncertain or because the risk ratio is uncertain.

Prostate cancer screening is the screening process used to detect undiagnosed prostate cancer in those without signs or symptoms. When abnormal prostate tissue or cancer is found early, it may be easier to treat and cure, but it is unclear if early detection reduces mortality rates.

Epidemiology of cancer

The epidemiology of cancer is the study of the factors affecting cancer, as a way to infer possible trends and causes. The study of cancer epidemiology uses epidemiological methods to find the cause of cancer and to identify and develop improved treatments.

Cancer screening

Cancer screening aims to detect cancer before symptoms appear. This may involve blood tests, urine tests, DNA tests other tests, or medical imaging. The benefits of screening in terms of cancer prevention, early detection and subsequent treatment must be weighed against any harms.

Active surveillance is a management option for localized prostate cancer that can be offered to appropriate patients who would also be candidates for aggressive local therapies, with the intent to intervene if the disease progresses. Active surveillance should not be confused with watchful waiting, another observational strategy for men that would not be candidates for curative therapy because of a limited life expectancy. Active surveillance offers men with a prostate cancer that is thought to have a low risk of causing harm in the absence of treatment, a chance to delay or avoid aggressive treatment and its associated side effects.

Cancer survival rates vary by the type of cancer, stage at diagnosis, treatment given and many other factors, including country. In general survival rates are improving, although more so for some cancers than others. Survival rate can be measured in several ways, median life expectancy having advantages over others in terms of meaning for people involved, rather than as an epidemiological measure.

References

  1. "Cancer survival rate: A tool to understand your prognosis - MayoClinic.com" . Retrieved 2009-10-11.
  2. Gordis, Leon (2008). Epidemiology: with STUDENT CONSULT Online Access. Philadelphia: Saunders. p. 318. ISBN   1-4160-4002-1.
  3. Varricchio, Claudette G. (2004). A cancer source book for nurses. Boston: Jones and Bartlett Publishers. p. 30. ISBN   0-7637-3276-1.
  4. "ACS : How Is Colorectal Cancer Staged?" . Retrieved 2009-10-11.
  5. 1 2 Brenner H, Arndt V (January 20, 2005). "Long-term survival rates of patients with prostate cancer in the prostate-specific antigen screening era: population-based estimates for the year 2000 by period analysis" (PDF). J Clin Oncol . 23 (3): 441–7. doi:10.1200/JCO.2005.11.148. PMID   15572727.
  6. Welch HG, Schwartz LM, Woloshin S (June 2000). "Are increasing 5-year survival rates evidence of success against cancer?". JAMA. 283 (22): 2975–8. doi:10.1001/jama.283.22.2975. PMID   10865276.
  7. Gloeckler Ries LA, Reichman ME, Lewis DR, Hankey BF, Edwards BK (2003). "Cancer survival and incidence from the Surveillance, Epidemiology, and End Results (SEER) program". Oncologist. 8 (6): 541–52. doi:10.1634/theoncologist.8-6-541. PMID   14657533.
  8. Cosetti M, Yu GP, Schantz SP (April 2008). "Five-year survival rates and time trends of laryngeal cancer in the US population". Arch. Otolaryngol. Head Neck Surg. 134 (4): 370–9. doi:10.1001/archotol.134.4.370. PMID   18427002.[ permanent dead link ]