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Curing cancer requires eliminating all cancer cells. The major modalities of therapy are surgery and radiation therapy (for local and local-regional disease) and chemotherapy (for systemic disease). Other important methods include hormonal therapy (for selected cancers, eg, prostate, breast, endometrium), immunotherapy (monoclonal antibodies, interferons, and other biologic response modifiers and tumor vaccines—see also Tumor Immunology: Immunotherapy), differentiating agents such as retinoids, and agents that exploit the growing knowledge of cellular and molecular biology. Overall treatment should be coordinated among a radiation oncologist, surgeon, and medical oncologist, where appropriate. Choice of modalities constantly evolves, and numerous controlled research trials continue. When available and appropriate, clinical trial participation should be considered and discussed with the patient.
Cure is defined clinically as the permanent absence of signs or symptoms of a disease; complete remission or complete response as disappearance of clinical evidence of disease; and partial response as a > 50% reduction in the size of a tumor mass or masses. Patients who appear to be cured may still have viable neoplastic cells that will eventually cause relapse. A partial response may lead to significant palliation and prolongation of life, but inevitably the tumor regrows. “Stable” disease indicates neither improvement nor worsening. The disease-free interval or disease-free survival reflects the interval between disappearance of cancer and relapse. Similarly, the duration of response refers to the time from response to the time of overt progression. Survival time refers to the time from diagnosis to death.
The disease-free interval often serves as an indicator of cure and varies with cancer type. For example, lung, colon, bladder, and testicular cancers are usually cured if a 5-yr disease-free interval occurs. Breast cancer, however, may recur even after 5 yr; thus a 10-yr disease-free interval is more indicative of cure.
Treatment decisions should weigh the likelihood of adverse effects against the likelihood of benefit; this requires frank communication and possibly the involvement of a multidisciplinary cancer team. A patient's preferences for how to live out the end of his life should be established early in the course of cancer treatment despite the difficulties of discussing death at such a sensitive time (see Medicolegal Issues: Advance Directives).
Last full review/revision November 2005
Content last modified November 2005
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