Should We Be Concerned that John McCain Has a History of Skin Cancer?
| In the beginning of September, John McCain will be the nominee of the Republican Party for President of the United States, the oldest major party candidate to run for a first term. Also unique to his candidacy is the well-documented publicly acknowleged history of a highly malignant and potentially life-threatening skin cancer, melanoma. Other presidents have had cancer; one, Grover Cleveland, surreptitiously and successfully treated it with radical surgery, but never has such a prior history been a potential issue in a presidential election. A legitimate question arises as to what the American people need to know about McCain’s ability to complete his term unimpaired by illness, prior to his acceptance of the nomination. With respect to his melanoma, this will undoubtedly be debated in the forthcoming election if it is not pre-emptively and properly addressed. While one of us briefly discussed this in a recent HNN post, quoting a March 9th article in the New York Times by Lawrence K. Altman, M.D., this article provides an updated, in-depth assessment of the chances Senator McCain would be able to complete his term without a recurrence of cancer. Dr. Altman’s prognostication--“for patients with a melanoma like Mr. McCain’s who remained free of the disease for the first five years after the diagnosis, the probability of recurrence was 14 percent during the next five years and death in 9 percent"-- is based on an article published in 1992. |
Since then, as medical science has advanced, the accuracy of staging has improved (1). Even more recent literature (2) admits that even employing present day criteria, recurrence rates were calculated from older data. The statistics for recurrence and fatality for stage IIa disease are actually considerably lower. The paper cited by Dr. Altman included a number of patients whose lymph node metastases were not yet identified. Since then, the sensitivity for diagnosing metastatic disease has improved with the popular adoption of sentinel node biopsy and Positron Emission Tomographic (PET) scanning. Therefore, the recurrence and fatality rates cited in the earlier study included an undetermined but significant number of patients who actually had more advanced Stage III, not Stage IIa, melanoma. As testimony to its value as a diagnostic tool, there is high correlation between the projected incidence of sentinel node metastases from clinical Stage IIa melanoma, approximately 15-20%, with the historic recurrence rate before sentinel node biopsy was performed.
Today (and in 2000), the standard of care for the initial surgery for Stage IIa melanoma includes sentinel node biopsy, as was done for Senator McCain. Since his sentinel nodes showed no evidence of disease, his risk of recurrence and death from melanoma is considerably lower than Dr. Altman states, more on the order of 2-3 % recurrence and 1-2% fatality at five years. These prognostic projections are based on numerous studies from leading U.S. melanoma centers including M.D. Anderson Cancer Center in Houston and John Wayne Cancer Center in Santa Monica, CA (an additional list of references will be supplied upon request).
Senator McCain’s known melanoma history is as follows:
1993-A small melanoma in situ, the most benign form of the disease, was removed from the left shoulder by local excision.
2000- A melanoma in situ was removed by local excision from the left arm. Another melanoma, 2 centimeters (about the width of the fingertip, see second photo at left) in diameter and 0.22 centimeters deep, was removed from the left cheek by wide excision with extensive lymph node dissection and biopsy, with no evidence of metastasis. The classification of this melanoma is based on the maximal tumor thickness of 2.2 mm without ulceration (loss of the surface layer), designated as T2a in the current international cancer staging system.
2003- A melanoma in situ removed from the nose by local excision (lower right photo).
The other important question to address, in light of the fact that Senator McCain is applying for a four year contract as the most powerful man on the face of the earth, is what diagnostic testing needs to be done, prior to acceptance of the nomination, in order to provide voters with the greatest assurance that the candidate will survive his term of office?
The risk of recurrence is fairly low and as time passes, it will continue to decrease but never to zero. Melanoma is notorious for recurring years if not decades after its initial diagnosis. Therefore, regularly monitoring is essential.
Melanoma may recur locally or may also metastasize to other organs, most commonly the liver, lungs, bowels, bones and/or brain. Metastases are often asymptomatic and may sometimes only be located on screening imaging studies performed periodically, even in the absence of any symptoms or signs of clinical recurrence. Metastatic disease is associated with a very guarded prognosis, with more than a 50% chance of dying of melanoma within the first year after it is identified. Brain metastases, the second leading cause of death, are especially malignant, being found in 90 percent of patients who die of melanoma, with an average life expectancy of well less than half a year when symptomatic. These figures underscore the necessity for updated, accurate staging studies.
Had Senator McCain not been running for president, screening might be as simple as a careful annual physical examination and chest x-ray. In consideration of the gravity and importance of the office and ability to obtain reliable information with virtually no downside risk, a reasonable diagnostic recommendation in this case would be, at the minimum, the combination a whole body Fusion PET/CT scan and a brain MRI with gadolinium enhancement. A paper published in 2007 (3) suggests an increased yield using whole-body MRI, but this as yet has not been employed on a widespread basis. These tests are complimentary, with different areas of sensitivity; PET being a measure of function and MRI one of anatomy. Objectively documented presence of metastatic melanoma would forebode a poor prognosis. A negative result on these two examinations would provide voters a reasonable assurance of a presently disease-free state and of the ability to complete a four year term.
(1) Gershenwald JE, et al; Multi-Institutional Melanoma Lymphatic Mapping Experience: The Prognostic Value of Sentinel Lymph Node Status in 612 Stage I or II Melanoma Patients; J Clin Oncol 1999; 17: 976-983
(2) Gimotty PA, Botbyl J, Soong S, Guerry D, A Population-Based Validation of the American Joint Committee on Cancer Melanoma Staging System. J Clin Oncol 2005 Nov; 23: 8065-8075
(3) Schmidt GP, Kramer H, Reiser MF, Glaser C., Whole-body magnetic resonance imaging and positron emission tomography-computed tomography in oncology. Top Magn Reson Imaging, 2007 Jun; 18(3): 193-202
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