Inl. J. Rediarion Oncobgy Biol. Phys.. Vol. t,. pp 393-394 Printed m th,: U.S.A. 8 Pergamon Press Ltd.. 1980.
TNM STAGING OF TESTIS CANCER GEORGE R. PROUT, JR., M.D.,
Professor of Surgery, Harvard Medical School, Chief of the Urological Service, Massachusetts General Hospital, Boston, MA Convention resists change. Pragmatists do not readily displace functioning units unless there is a clear advantage produced by the introduction of new and different units. The more independent people are, the less likely they are to abandon old fashions and take up new, unless there is a perceivable advantage in the changing of old for new. Physicians are fiercely independent; one of their basic characteristics is not to abandon something, a medical remedy, an operative procedure, if it works fairly well. Penicillin and insulin need no selling. The advantage was as obvious as that of an appendectomy for acute appendicitis. Conversely, where the shadings are much less distinct, change may be very difficult to achieve, although the change is clearly for the better. In this issue Batata et al use the classification of the .4merican Joint Committee to stage testicular carcinoma. This is a noteworthy event of major proportions; it is not only a departure from the various staging systems in vogue (a new one appeared in 1976) but it demonstrates that TNM can be made to function, even in the United States. Specialists tend to generate staging systems that change as new information is acquired. This provides for a level of communication within the specialty, however, it is often a barrier to specialists/oncologists who are also obliged to play a role in designing diagnostic and therapeutic strategies.3 They may have great difficulty because the vocabulary is strange and/or everchanging. Furthermore there are usually no rules set down to provide for a rational progression of change. Urological staging systems, with the exception of testicular carcinoma, have focused on the primary growth (T), leaving the domains of nodes (N) and other metastatic sites (M) to be included only where they are absolutely relevant. One may reasonably infer from this that clinicians know when they’re licked. Destruction of the primary growth by one means or another remains the major means for curing solid tumors. If nodal involvement in patients who have bladder or kidney carcinoma all but abrogates cure, then why bother with a new, taxing system of classification? The reasons are straightforward. Batata and his assoAccepted for publication
ciates did not find any relationship between the T category and survival; they did find a difference in survival if the nodes were microscopically or grossly involved. Systems that prevent analyzing and thinking of the domains of tumor activity in such a fashion inhibit the development of new ways of treating disease. Another good reason is that one need not search for the latest paper by a given author in order to stage a patient. The American Joint Committee classification provides rules for staging. As information is collected and assessed the TNM system for any tumor may be changed, however, it will not be changed until a consensus of the oncological community has been reached. Such changes will appear in the Manual’ only after a previously stipulated period of testing has occurred. There is yet another side to staging. Editors have often overlooked the fact the authors sometimes fail to mention whether the stages of the population who were incorporated in a given analysis were clinical or pathological, thus adding even further to the gap in communication. We once had a simple, untidy but fairly useful staging system for prostatic carcinoma. “A” was the patient who had a benign-feeling gland which was removed for symptoms of obstruction and tumor, usually a few fields of well-differentiated carcinoma, was found. “B” was the isolated 1 cm nodule, “C” was extraprostatic extension without clinical evidence of metastases and “D” was found in the patient with clinically metastatic disease (regardless of what the primary tumor was like-size, extension or grade). The Veterans’ Administration Research Group found five stages that overlapped these four. The urological community then discovered a phenomenon that was known all along: patients with benignfeeling glands who had a lot of tumor, especially poorlydifferentiated tumor, didn’t survive nearly as well as the lower-burdened A’s; hence, “A,” and “A2.” A couple of nodules or one completely indurated lobe suggested an entirely different outlook from the little nodule of Stage B; now we have “B,” and “B2” (note that the system has no easy means of expressing the status of regional nodes). We discovered in Stage C that large Stage C’s behaved
2 Jamuary 1980.
differently from small ones; ergo “C,” and “C,.” However, if the patient has had a lymphadenectomy and positive nodes are found, he becomes a D, and thus the old “D” becomes “DZ.” The D, specifies neither sites nor numbers of positive nodes, yet there is already a body of information which indicates that patients with scant nodal disease have a thoroughly different likelihood of progression than the patients with multiple positive nodes. Here, the American Joint Committee classification can be depended upon to clarify many circumstances. This requires that.we return to an item that Batata et al seem to have overlooked. The American Joint Committee went a step further than the International Union against Cancer (UICC) staging system in proposing different classifications. On pages 3 and 126 of the Manual’ are rules that are designed to require stipulation of how the staging information was acquired. Was the staging by clinical, surgical or pathological means? Unfortunately, the early assumption was that one might have a pure surgical-evaluative or pathological stage. This is not encountered in practice. Not without some justification, Batata and his colleagues have mixed clinical, surgical-evaluative and’pathological staging in their analyses. It’s terribly convenient and we all understand what they mean this time, however, the trap is still there. The American Joint Committee should recognize that one may have a clinical stage where the domains of tumor, TNM, are assessed and that this assessment will be kept as the (c)linical stage, never to be changed or lost. For instance, radical orchiectomy reveals an embryonal carcinoma confined to the body of the testis; a lymphangiogram (LAG) is doubtfully positive, chest film, tomograms and serum markers are negative. The stage is
cT1NoMo. A para-aortic node dissection is performed and three nodes are found to be microscopically involved. The American Joint Committee has made no provision for adding the specific information obtained. It can be added, of course, by staging the patient cTlp(athological)N2cMo. Later, the patient develops a positive chest film, changing him to cTlpN2cM(pul). A biopsy of the lesion reveals embryonal cell carcinoma and to keep pace with the disease and the acquisition of information, ther patient changes to cTlpNZpM(pul). The introduction of a radiotherapeutic program or one of chemotherapy might be made at any stage. The report would clearly state the patient’s initial clinical stage and the stage when therapy was commenced, and one would know precisely how each domain was defined. The proposal to use subscripts for T, N and M is currently under consideration by the Executive Committee of the American Joint Committee. We assume some accommodation will be made. Little damage can result as long as the initial stage is kept and the subscript indicators are accurate. If the staging is accurate, we may find things that we did not know existed.2 Our current problems are how to incorporate CBT, serum markers and microscopic versus grossly involved nodes into the “testis” system. Changes in diagnostic and therapeutic procedures occur at a pace which partially cripples some of the TN M systems in three or four years. Regardless, the American Joint Committee classification is far better th,an the alphabet soup we’ve been cooking up every so often, even with a liberal sprinkling of Arabic and Roman numerals. These ad hoc additions can only diminish communication, add to the confusion of staging and move us farther away from a common taxonomy for expressing the extent of neoplastic states.
REFERENCES 1. American Joint Committee for Cancer Staging and EndResults Reporting of the American College of Surgeons: Manual for Staging of Cancer 1977. Chicago, American Joint Committee, 1977.
2. Prout, G.R., Jr.: Classification and staging of bladder carcinoma. Sem. in Oncol. 6: 189, 1979. 3. Rubin, P.: Current concepts in genitourinary oncology: A multidisciplinary approach. J. Ural. 106:3 15-338, 197 I.