On Dec 28, Cristina Fernández de Kirchner, the President of Argentina, received some bad news. She has been diagnosed with thyroid cancer, and must take a leave of 20 days to undergo surgery (on Jan 4). The discovery of the cancer was a result of routine screening.
The Economist blog reported this unhappy occasion, telling readers that "Ms Fernández is the latest of a series of South American presidents to fight cancer." Perhaps we are supposed to infer that being leaders of South American countries is a hazard to one's life (otherwise, what's the point of writing about it?). The Council of Foreign Relations even picked as a "top trend of 2011" in Latin America "the Region's Presidents' Battle Cancer".
The next day, Reuter's reporter Daniel Wallis told us that Venezuela's President Chavez has taken the correlation as evidence that "the United States might have developed a way to give Latin American leaders cancer."
Back in October, Kirchner won re-election by a landslide. Her supporters within Argentina are numerous. On Jan 3, the day before she went under the knife, they held an overnight vigil. According to the Washington Post (link), "At 1 a.m. on the morning of her operation, supporters assembled in various plazas and squares around the country, and remained there until it was finished."
Also on Oct 3, on a Financial Times blog, Jude Webber suggested that President Kirchner has benefited and will continue to benefit in public opinion from her illness:
According to this poll published last month, four days before the routine exam which revealed she had a cancerous tumour, Fernández’s popularity was 67 per cent – well above the 54 per cent she secured in the October elections. After the op, the only way is up, at least initially, pollsters say.
The Washington Post piece mentioned above has another angle. The reporter describes "what’s interesting is the panic that her illness has inspired".
It was announced that the three-and-a-half-hour surgery to remove her thyroid gland went successfully. CNN found a supporter who opined: "The truth is I was praying a lot, with all my strength, and now I feel very happy. I think the Virgin has granted a miracle."
Good news arrived, confirming that the cancer has not spread, and the President could get back to work soon.
On Jan 7, the doctors conceded that the initial diagnosis was a "false alarm"; Kirchner did not have cancer after all. According to the FT, the false positive only occurs in 2% of cases. So Kirchner was very unlucky.
How does a false alarm occur? According to Dr. Bianco, cited in this ABC News blog, typically, a lump is identified, and if it is large enough, a biopsy is taken, which means cells from the thyroid gland are taken and examined for signs of cancerous growth.
Next, Dr. Braunstein specifically tells us that doctors deliberately cause "false positives":
If there’s about a 20 percent to 30 percent chance those cells are cancerous, many doctors — including Braunstein — recommend removing the thyroid gland.
In other words, there is no simple black-or-white test of whether cancer is present in the cells. This, I suspect, is also due to the fact that only a tiny sample of cells are examined -- and the diagnosis is a general statement not just of the examined cells but of the entire gland. So there is a margin of error.
Based on what Dr. Braunstein is telling us, about 70 to 80 percent of the removed thyroid glands would be cancer-free. The chance of a "false positive' is actually really high (if you have been asked to have the operation)!
How does one reconcile this with the other report that the false positive rate is 2%. I'm not so sure.
As a side effect of this surgery, Kirchner would need to take hormone pills for the rest of her life.