The life span of patients diseased with the same cancer type differs by dozens of times under the similar treatment. According to opinion of the Russian Scientific Center for Radiology and Surgical Technology specialists, this circumstance indicates at complete suddenness of therapy results. Apparently, the outcome depends on the factors outside the sphere of traditional treatment and diagnostics methods.
The researchers have investigated survival curves of the patients suffering from non-small cell inoperable carcinoma of the lung or the inoperable locally advanced oropharyngeal carcinoma of the head and neck after chemical radiation therapy, as well as survival curves of the patients diseased with breast cancer, who have undergone the operation and radiation therapy. These curves very often have the shape typical of probability processes. In other words, the result of therapy is chancy: it may or may not help.
According to the survival curves, the most favorable forecast is applicable to patients with breast cancer in the initial stage. In case of such disease, the patients can live rather long: their quantity decreases approximately by twice within 30 months. However, this period differs little from the 38-month period – the time when half of patients who did not get any treatment usually die. As the tumor grows, there appears a group of quickly dying individuals among the patients. The specialists still do not know why such group occurs. Nevertheless, the breast cancer patients of the same stage and with the same treatment form two groups: the group of quickly and slowly dying patients, and it is unknown who will get into which group. The share of quickly dying patients increases as the tumor grows. In case of cancer of the lung, head and neck, there are no “long-living” patients. All patients die quickly, their number reduces by twice within 4 to 8 months. However, event in this group, physicians also note heterogeneity in terms of longevity. Mechanism of occurrence of the observed heterogeneity is connected (in the researchers’ opinion) with individual peculiarities of physiological systems of the patient’s organism life support and require further investigation.
The researchers note that the time of an oncological patient’s death is a probability event, that is, it is impossible to predict. Some of the patients will live for a month or two, but some will survive for several years. The treatment modes applicable today are unable to overcome this uncertainty. Regardless of localization and conducted treatment, the patients divide into two categories – the quickly- and slowly-dying ones. To make results of therapy predictable, it is necessary to pass on to fundamentally new therapeutic technologies, therefore further investigations are required.