Sabtu, 6 Julai 2013
Rawat Kanser Guna Imun Sistem
Rawat Kanser Guna Imun Sistem
In the last 25 years, immunology has answered one of the central questions about cancer – why cancer cells are not destroyed by the patient’s immune system. Based on the research of Dr. Lentz and others, we now know that cancer cells create inhibitors to shield themselves from attack, much the way military aircraft produce “chaff” to fend off defensive fire.
Using a technology akin to dialysis, Immunepheresis removes these inhibitors from the patient's bloodstream, eliciting a natural immune system response that in most cases leads to rapid tumor shrinkage. The method has been used in human clinical trials for over 15 years, and in several hundred patients, with consistent, encouraging data on efficacy and safety.
Immunepheresis appears to be effective in a wide range of solid tumor cancers, though not in all patients: the key prognostic variables are (a) cancer stage and (b) strength of the patient's immune system before treatment begins.
Importantly, Immunepheresis has usually shown results that are better than chemotherapy or radiation in terms of killing most malignant tumors. Even in patients with Stage IV disease; multiple metastases and major tumor burden; extensive prior chemotherapy; and exhaustion of conventional therapeutic options, Immunepheresis has shown significant clinical responses (i.e. >50% reduction in measurable tumor volume).
There are a number of reasons this therapy especially interests immunologists:
1. The apparent universality of its efficacy in cancers of varied types; this implies a common immunologic mechanism;
2. The high rate of tumor necrosis (cancer cell death) that can be achieved without collateral harm to the patient;
3. No ‘dose limiting’ toxicity, or long-term damage to the patient’s immune system, as experienced with chemotherapy.
4. The relatively mild, short-term side effects, in dramatic contrast to what the patient endures with chemotherapy or radiation.
5. The short initial term of therapy needed to confirm positive response;
6. The response rate even in patients who have exhausted all other therapeutic options; and
7. The expected lack of long-term complications such as the secondary cancers that are known to follow chemotherapy and radiation.
In theory, Immunepheresis in particular and immune therapies in general hold the potential to eliminate virtually every cancer cell in the body over time. Given the newness of the therapy, we can only measure initial, not long term response. In many but not all new cancer therapies, such favorable initial response has proven to be predictive of improved intervals before disease progression and ultimately of improved rates of survival.
Basics of Immunepheresis
A standard dialysis central venous catheter is surgically implanted. Blood is withdrawn from the catheter through specialised tubing to a machine that filters TNF inhibitors out of the blood and returns the blood to the patient through the same catheter. Removal of the inhibitors frees the immune system to attack the cancer. The lower the inhibitor level, and the longer it is maintained, the more effective is the resulting tumor inflammation in effecting tumor necrosis.
Typical sessions last 4 - 6 hours a day. Skilled nurses and doctors are continually present.
Side effects are typically mild and short-lived. Patients often experience a mild flu-like feeling, low-grade fever and fatigue due to the immune unblocking. A patient during treatment can either doze, eat and drink, talk, read, listen to music, watch a movie or sleep. If tumor-specific inflammation is created, the patient can experience a dull ache or pain in the tumor site. Cutaneous tumors can become red, hot, tender and swollen. This tumor tenderness usually resolves within hours of treatment.
Early Stage Cancer Patients
Early stage (Stage I-III, pre-metastatic) patients may be the best candidates for Immunepheresis. Since most patients have been Stage IV, we have relatively few cases of early stage disease. However, among those few, improvement has been consistent and significant, including apparent remission in several cases. Among the reasons that make such results plausible in early-stage patients: their cancers tend to be less extensive, their health more robust, and they sometimes have not received extensive prior chemotherapy. Any co-morbid condition, especially those that compromise the immune system, might lessen the efficacy of the therapy.
Late Stage Cancer Patients
Stage IV patients generally show a better response to Immunepheresis than would generally be expected from chemotherapy and/or radiation. Despite suppression of their immune systems through prior chemotherapy and radiation, about two-thirds of Stage IV patients show a positive response to Immunepheresis in terms of tumor inflammation and necrosis – the key signs of cancer cell death. This suggests that while Immunepheresis does not help every Stage IV patient, it is a better option than any other systemic therapy, including chemotherapy.
The key variables for Stage IV patients are high tumor burden, weaker general health, an immune system compromised by extensive cytotherapy and/or radiation, or cachexia.
Stage IV patients can also receive a three-week trial of Immunepheresis, after which their response is evaluated. If their response has been positive, further treatment can be considered. Some patients require many weeks, even months, of treatment to obtain maximal response. The good news is that such patients are showing continued improvement.
Referring physicians and their patients are welcome to contact the Foundation to inquire about treatment. You may contact us by phone or complete the on-line patient information form.