Sir, I refer to the news item 'Food preservatives could aid cancer fight' in the 7 December 2012 issue of the BDJ (213: 543) and would like to add some comments.

Our charity has been working for some years using E-304 (aka palmitoyl ascorbate or ascorbyl palmitate [USA]) which has been found to be efficacious in extending life in cases of colon cancer deemed inoperable or with a prognosis of three months or less to live. E-304 is widely used in the food industry and has an LD50 of 3000 mg/kg (worst case in guinea pig) so it is inherently safe. At an oral intake of 1 g/day stirred into yoghurt it has proved to be easy to take and effective. In vitro it is a powerful anti-angiogenic. It is also lipid soluble and therefore likely to penetrate the host/tumour interface. Here the product of its interaction with homocysteine lactone produced by tumour cells into the area of contact with host tissue would provide an opportunity for formation of the toxic 3-mercaptopropionaldehyde around and within the cell membrane and subsequent apoptosis of the tumour cell.

These two properties alone are sufficient to suggest it is of prime interest in cancer control. E-304 has also been used for some years as a means of keeping low Ca125 counts in recovering ovarian cancer cases where hormonal treatment has been of limited value.