General Rules of Tumor Therapy

By Dr. Vishaal Bhat on Monday 19 November 2007 with 0 comments



Elaboration of a therapy plan for tumors of the oro-facial system has to be made in an interdisciplinary collaboration (maxillofacial surgeon, radiotherapeutist, chemotherapeutist, oral prosthetist, anesteziologist). The following main factors have to be considered for selection of modes of therapy and their combinations:

  1. Tumor disease staging (classification of a tumor)

  2. Primary tumor grading (tumor biology, differentiation)

  3. General condition and age of a patient

  4. Additional general and other illnesses

  5. Patient’s social situation and profession

  6. Perspectives of a psychosomatic rehabilitation


The fundamental pillars of therapy of the orofacial area malignant tumors are surgery and radiotherapy. Over the last two decades, the cytostatic chemotherapy has been also utilized. Combination of the three methods represents so called integrated oncotherapy which is radical enough as a whole while still respecting a quality of life after the therapy as well as re-socialization of a patient.

Surgery employs many procedures of various radicality. Among these belong: extirpation of small restricted tumors (salivary glands, skin and subcutis), excisions with a safety rim (lips, buccal and palatal mucous membranes), partial resection (the tongue, oral base), subtotal resection (maxilla), hemiglossectomy (half of the tongue), hemimandibulectomy (half of the lower jaw). The nodal system can be extirpated (a solitary lymph node), exenterated (submandibular area, supra-hyoid block resection), or dissected (radical one-sided or double-sided neck dissections). Soft tissue defects are replaced with pedicle flaps from adjacent tissues or by transfer of free or stemmed grafts from the temporal or chest areas. Extensive supra-radical resections are being abandoned at present due to functional and esthetic degradation of the face. Supra-radical surgery is being replaced by an aggressive combined oncotherapy which includes radio-chemotherapy. In spite of that, surgery remains the basic and primary therapeutic method of oncological therapy.

Radiotherapy is either independent or combined onco-therapeutic method. It can be applied before an operation as a preparation for the surgery (restriction of metastasizing components of a tumor, control of sub-clinical foci around a tumor, reduction of the tumor mass) or after the surgery for suppression of residual malignant disease at the tumor peripheral area and regional lymph glands. Both modifications utilize irradiation of tumor by the dose of 54 to 60 Gy (Gray) delivered over the period of 6 weeks. If the irradiation is divided into two doses of 30 Gy before and after a surgery, it is called the “sandwich” technique. At indicated cases, e.g. tumors T1 of the lips, radiation therapy is applied as a mono-therapy (without a surgery).


Chemotherapy got promoted from its original position of a supplementary therapy into a valuable method of a therapeutic stock of techniques. At the oro-facial area is applied mainly in the form of a regional intra-arterial infusion of selected cytostatics. During an intra-arterial application, the tumor area is washed via its supplying artery by a several-fold (minimum of four-fold) higher concentration of cytostatic and anti-mitotic (oncolytical) substances than it would be during a systemic administration per venam or per os. The input supplying artery is arteria carotis externa and its branches which supply all organs and areas of the oro-facial region. The mostly used cytostatic drugs are antimetabolites Methotrexat and Fluorouracil, the cytostatic antibiotic Bleomycin, the anti-mitotic drug Vincristin, anthracyclin Epirubicin and the cis-platinum derivatives. These drugs are usually administered in combinations, out of which the program VBM (vincristin, bleomycin, methotrexat) has been proven to be the most successful. The aims of chemotherapy are down-staging (reduction in size or macroscopic disappearance of a tumor) and down-grading (reduction of the biological aggressivity of a tumor). It creates objectively better initial situation for subsequent surgical intervention and radiotherapy. A chemotherapy which is designed in such a way is called chemo-induction.

The following schemes depict rational therapeutic procedures for primarily operable tumors (T2) and non-operable tumors (T3) which require a pre-operational preparation. The three-phase program is suitable for operable (resectable) tumors:

  1. chemotherapy (local and systemic effects)

  2. surgical resection (local effects)

  3. radiotherapy (regional effects)


In case of an uncertain operability of a primary tumor, the four-phase program is appropriate:

  1. chemotherapy (local and systemic effects)

  2. pre-operational radiotherapy (30-40 Gy)

  3. surgical resection (local and regional effects)

  4. post-operational radiotherapy (30-40 Gy)


Follow-up checking

Even a primarily successful strategy of curing the head and neck tumors suffers from relatively frequent failures. Reasons may be early (up to 2 years) and late (up to 5 years) local recurrences as well as regional and remote metastases. In order to achieve a definite success of therapeutic efforts, it is very important to follow patients in a long term after an oncological therapy has ended. The purpose is prevention and timely identification of eventual recurrence of a secondary tumor. An early recurrence can be dealt with if cured on time and in a rational way. A patient with a malignant disease should be followed up for the rest of his/her life. The follow-up examinations should take place once every month during the first six months, once every two months during the second half a year, once every three months up to 2 years, and every 6 months from 2 to 5 years. After the fifth year, a patient undergoes a follow-up examination once every year and receives specific instructions how to proceed in case of eventual changes of a local finding or a general condition. These follow-up visits are executed at specialized clinics in close collaboration with a personal care physician or a dentist. The first recurrence has to be viewed the same way as a primary tumor and the course of action towards its elimination has to be as persuasive as at the first contact with a tumor.


Perspective

Studies on large sets of patients have shown that the five-years survival is reached by about 50% of patients who had suffered tumors at the oro-facial area. Since an efficient cure for cancer has yet to be discovered, it is necessary to focus on a more effective organization of the oncological care, especially in the field of early diagnosis of primary tumors and more complete interdisciplinary cooperation of specialists. At present, this is the way of reaching the goal, set by the World Health Organization for oncology - to increase the rate of cured oncological diseases from today’s 50% up to 65% by the year 2000. Reaching this goal indeed requires a great deal of medical morale. A patient suffering a malignant disease is the patient “sui generis” and that is why his/her physician has to be equipped with an extraordinary ability of empathy with a patient’s psychological state and social situation. A personal physician should never abandon a patient since he/she is the solid point for him, which is said to have a capacity to move the universe.

Category: Stomatology Notes

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