Chemotherapy is the cancer treatment most likely to weaken the immune system. Chemotherapy medicines target rapidly dividing cells, which cancer cells are — but so are many of the normal cells in your blood, bone marrow, mouth, intestinal tract, nose, nails, vagina, and hair. So chemotherapy affects them, too. Cancer cells are destroyed by chemotherapy because they can’t repair themselves very well. Your healthy cells typically can repair the damage from chemotherapy once treatment ends. (One notable exception is nerve cells in your hands and/or feet, which can be permanently damaged by certain chemotherapy medications — a condition known as peripheral neuropathy).
Cancer development and its response to therapy are strongly influenced by innate and adaptive immunity, which either promote or attenuate tumorigenesis and can have opposing effects on therapeutic outcome. Chronic inflammation promotes tumor development, progression, and metastatic dissemination, as well as treatment resistance. However, cancer development and malignant progression are also associated with accumulation of genetic alterations and loss of normal regulatory processes, which cause expression of tumor-specific antigens and tumor-associated antigens (TAAs) that can activate antitumor immune responses. Although signals that trigger acute inflammatory reactions often stimulate dendritic cell maturation and antigen presentation, chronic inflammation can be immunosuppressive. This antagonism between inflammation and immunity also affects the outcome of cancer treatment and needs to be considered when designing new therapeutic approaches.
Many cancers can recur decades after first being discovered and treated, especially if radiation is also part of the treatment plan. And if it isn’t the original cancer that was treated that comes back, it may be some other form. Biochemical individuality, lifestyle, age and so many other environmental components all factor into your survival rate.
As chemotherapy medicines damage the bone marrow, the marrow is less able to produce enough red blood cells, white blood cells, and platelets. Typically, the greatest impact is on white blood cells. When you don’t have enough white blood cells, your body is more vulnerable to infection.
Although most chemotherapy medications can have an impact on your immune system, how much of an impact depends on many factors, such as which medicines you’re taking and in what combination — having two or three at once is more likely to affect the immune system than having one
- how much medicine is given and how often medicine is given (dosing)
- how long treatment lasts
- your age and overall health
- other medical conditions you have
Some chemotherapy medicines are taken by mouth, in pill form, while others are given intravenously — through a vein in the chest, arm, or hand — at a hospital or clinic. If you’re having intravenous treatment, ask that it be given on the opposite side of the body from where you had your surgery. The injection site poses some risk of infection, and since breast cancer surgery usually removes lymph nodes, you definitely want to minimize that risk on the affected side of your body. (If you had cancer in both breasts, choose the side of the body that had less extensive surgery or fewer lymph nodes removed, if possible.)
One of the main reasons for cancer chemo-resistance is increase patient drug tolerance due to increase in cellular drug excretion of the chemotherapeutic. Furthermore chemotherapeutic drugs are generally not specific for particular cancers, they generally affect only cells that divide, dormant cancer stem cell are generally not effected by chemotherapy.
Chemotherapy approach also ignores the fact that most cancers are heterogeneous and not homogeneous, this is a further cause of chemo-resistance. Other possible reasons include: increase drug detoxification, alter drug receptor sensitivity, increase cellular repair mechanism and genetic polymorphism and altered pH gradients across cancer cells and poor cellular immunity. In many case chemotherapy is a self defeating immune therapy as most chemotherapeutic drugs decrease white cell counts. Chemotherapy can be improved by using a ketogenic diet with the chemotherapy and inhibiting or down regulating drug excretion cellular transporters with the supplementation of luteolin, quercetin, curcumin, green tea polyphenols
The timing of different chemotherapy regimens varies. Typically, you would take the medication(s) for one day to several days, wait a couple of weeks to give the body time to recover, and then start the cycle again. Treatment can last for anywhere from 3 to 6 months. During that time, you would be considered to be immunocompromised — not as able to fight infection. After finishing chemotherapy treatment, it can take anywhere from about 21 to 28 days for your immune system to recover.
Cancer can weaken the immune system by spreading into the bone marrow. The bone marrow makes blood cells that help to fight infection. This happens most often in leukaemia or lymphoma, but it can happen with other cancers too. The cancer can stop the bone marrow from making so many blood cells.
Certain cancer treatments can temporarily weaken the immune system. This is because they can cause a drop in the number of white blood cells made in the bone marrow. Cancer treatments that are more likely to weaken the immune system are: