No. Teflon and all other commercially available materials suitable for cooking are safe and adequate for people during cancer treatment.
There is no justification for the use of porcelain utensils as the only safe material for cooking during cancer treatment. Any commercially available material can be used safely. Nevertheless, it is recommended, not only for people affected by cancer but for the whole population, that utensils that are in contact with food should be of good quality, suitable for cooking and in good condition, without scratches or any other damage.