How come a good anti-cancer drug suddenly doesn't work?

Medication is an important measure in the fight against cancer in humans, such as chemotherapy drugs, targeted drugs, or anti-tumor hormone drugs.
effective anti-cancer drugs can work in different ways, killing tumor cells, shrinking and disappearing them, or keeping them under control, preventing them from growing for longer periods of time.
, but unfortunately, in many cases, the therapeutic effects of anti-cancer drugs do not last long.
We see or hear in life that some cancer patients start treatment with medication that affects the size or growth of the tumor, but then the tumor starts to grow again despite continuing to receive the drug.
's going on? How can the original effective anti-cancer drug be ineffective? This is likely to be related to so-called tumor resistance.
is one of the main causes of cancer treatment failure.
of drug resistance is related to a variety of factors, such as abnormal mutations in cancer cells and changes in the micro-environment of tumors.
we know that cancer cells are caused by abnormal mutations in normal cells, but mutations don't stop there.
that even if cells have become cancerous, this similar process can help cancer cells continue to mutate, adapting them to anti-cancer drugs, or developing resistance to cancer drugs.
when treated with an anti-cancer drug, for cancer cells is "a matter of choice, survival of the fittest."
ideally, every cancer cell in the tumor would be killed.
if even a single cancer cell happens to mutate and become resistant to the drug, it is likely to survive and eventually grow into a new tumor.
once drug-resistant tumors developed in this way, the drug, which had been able to shrink tumors, would no longer work.
cancer cells are resistant to an anti-cancer drug in many ways.
hormone drugs, which are commonly used to treat some estrogen-driven breast cancers.
can interact with estrogen-like estrogen on the surface of breast cancer cells, sending signals that cause cancer cells to grow.
hormone drugs can kill or inhibit cancer cell growth by blocking this interaction or lowering estrogen levels in the body.
However, if cancer cells cause specific mutations in estrogen-like subjects, estrogen is no longer needed to signal division and growth to cancer cells, resistance to the hormone-like drugs becomes and hormone-based drugs no longer work.
with other drugs, such as chemotherapy.
Cancer cells can develop a number of different mutations, including preventing the drug from entering the cancer cells in the first place, "sending the drug back" outside the cancer cells before any damage is possible, or helping cancer cells quickly repair chemotherapy-damaged DNA to help them avoid the effects of chemotherapy drugs.
tumor resistance may also be related to the local environment in which cancer cells exist, i.e. changes in the micro-environment of the tumor.
tumors are made up of different cells, which may have different genetic, presumed and metabolic characteristics and are sensitive to treatment.
tumors are also made up of immune cells, blood vessels, fibroblasts, and other cells or components that interact with cancer cells.
interactions between these different cells or components often promote tumor development, development and resistance to treatment.
currently, the main ways to deal with tumor resistance include the use of a different form of action of anti-cancer drugs or the use of combined therapy.
this, however, does not completely avoid tumor resistance, which over time is likely to eventually develop resistance to one or more new cancer drugs.
resistance is one of the biggest challenges in cancer treatment.
it is found in almost all types of cancer and in all anti-cancer drugs, including molecular targeted therapy, immunotherapy and chemotherapy.
resistance also makes patients from the beginning of effective treatment of joy, hope, to treatment is ineffective, tumor development of helplessness, loss, bring emotional ups and downs, cancer treatment and prognostic adverse effects.
to address why cancer drugs produce resistance to cancer, and to find ways to overcome or prevent it, is the goal of on-the-job research being carried out by many scientists.
we look forward to early research to find ways to address drug resistance, pave the way for better treatment for cancer patients, and improve survival possibilities.
a reference: 'Why do some cancer treatments stop work after so long?' Retrieved Nov 20, 2020, from Cancer Drug Resistance: Unraveling Its Complexity. Retrieved Nov 20, 2020, from Managing Cancer as a Chronic Oil. Retrieved Nov 20, 2020, from