Reacción a "Talc is classified as "probably carcinogenic to humans" by the IARC"

The IARC agency, which is part of the WHO, has classified talc as a ‘probably carcinogenic’ agent, meaning that exposure to it might cause cancer. This classification of talc is based on existing studies that suggest, though not with sufficient robustness, that talc could increase the risk of cancer, particularly ovarian cancer. 

This does not mean that someone who has used talc once or even regularly is clearly at risk, as the risk of developing cancer depends on the dose of exposure, duration, and manner of contact with the talc. 

The studies supporting this classification have many biases, that is, certain confounding factors that prevent us from fully understanding or predicting the relationship between talc use or exposure and cancer. 

In animals, it has been observed that talc has properties that produce malignant tumors, but this exposure to animals is experimental and does not always replicate what happens in humans. However, it demonstrates talc's capability to induce tumors in laboratory settings. 

In human studies, there is a significant confounding factor: asbestos, a harmful substance that induces tumors, has been a contaminant of talc. Therefore, classic studies on talc usually included talc contaminated with asbestos. Thus, for this classification, studies using talc (without asbestos influence) have been used. Focusing on these studies, one of the problems is that in professional talc mining studies, most of the participants were men, and the presence of women was very low, so it cannot be correlated in this case with the risk of ovarian cancer. 

The two studies supporting the recommendation included women who used talcum powder applied to the genital area. Applying talc in this area showed a slight increase in ovarian cancer, but not significantly, in a first study that included more than 250,000 people in the United States. A second analysis of 8 case-control studies, including more than 18,000 people (divided into cases, those who ever used talc vs. controls, those who never used talc), showed that women who had used genital talcum powder had a slightly higher risk of serous infiltrating ovarian tumors, clear cell tumors, and borderline serous tumors in a statistically significant manner. In those who used talc in other locations (i.e., not in the genital area), no increased risk of cancer was observed. 

In summary, and based on this new classification (although not with great robustness), it would be advisable to avoid, as much as possible, the use of genital talcum powder, particularly in women. However, this does not mean that previous use of talc will cause cancer or that prior exposure to this agent will be clearly responsible for the appearance of a tumor.