Day 16 – LUNG CANCER: UNDERSTANDING YOUR PROGNOSIS [read more=”Click here to Read More” less=”Read Less”]
Lung cancer across all subtypes has long been a grim disease, with a poor prognosis and short survival times relative to other types of cancer. However, this is changing with rapid advancements in treatments and symptom management. Furthermore, all of the statistics have numerous caveats which limit their applicability to individual cases and make interpreting them a challenge.
What is undeniable is lung cancer is a very dangerous disease with a high risk of mortality. The different subtypes have very different stats however, though all are improving. Lung cancer is no longer the death sentence it once was.
The most commonly cited statistic for understanding cancer lethality is 5-year survival rate. This immediately should raise a concern – 5-year survival rates by definition must be backward-looking, as they are calculated using vast amounts of data at least 5 years old. So, they do not take into account the most recent advances in treatment, which have been quite dramatic, especially for the adenocarcinoma and squamous cell subtypes of NSCLC.
Moreover, survival rates are not predictive even for people with the same stage of cancer for a number of reasons. Among these:
- Spread of the disease: As an illustration, suppose two have stage IV adenocarcinoma. Stage IV simply means the disease has spread. Now, take a person who has a small primary tumor with a single distant metastasis to the adrenal gland. This person would have a very different (and much better) prognosis than a person with multiple metastases, larger primary tumor(s) and cancer in more critical organs, such as the liver. Even more detailed staging techniques do not capture all of this nuance.
- Symptoms and treatments: Beyond the direct impact of cancer spreading to different organs, cancer causes a nearly infinite number of secondary health problems, from seizures to renal failure to pain. These secondary health problems themselves can be dangerous, and the treatment of them can also be harsh on the body. Additionally, people react very differently to the cancer treatment itself. For instance, some patients breeze through chemo with few side effects, while other people react so severely that they need to discontinue treatment or even pass away as an indirect result.
- Co-morbidities: Lung cancer disproportionately affects older people with a history of smoking. Not surprisingly, this same subset of patients is also prone to a variety of other illnesses and diseases, from high blood pressure to COPD, which can be lethal and/or necessitate difficult treatments. Many people with cancer who pass away do not die of the cancer, but of strokes, heart attacks and other adverse events. To add further complexity, while a younger and healthier person would generally be better placed to endure the disease and treatments, some evidence suggests cancer which strikes younger people without behavioral causes (i.e. non-smokers) might be more aggressive in many cases.
- Genetics and microbiology: Everyone’s cancer is different. The tumors of two people with the same exact type of cancer, stage and degree of spread may have very different genetic characteristics or other microbiology. Though there have been rapid advancements in the understanding genetic mutations and their implications, this field of study is truly in its infancy. Already there are multiple types of mutations which suggest different levels of aggressiveness of the cancer, and there are targeted and immunotherapies which work on tumors with specific mutations. A patient “lucky” enough to have one of these may be effectively treated with drugs that have few serious side-effects.
- Response to treatment: Response to standard treatment (e.g. chemotherapy, radiation, etc.) heavily influence the prognosis. Treatment can be highly effective with some patients, even leading to the eradication of all visible disease. Unfortunately, some cancers do not respond at all to treatment, and the patient therefore has a much worse prognosis. At present, the reasons behind the efficacy of treatments on different patients are largely unknown.
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