We do write occasionally about male breast cancer, although it accounts for no more than 1 or 2 per cent of breast cancer cases in the UK.

If our reader’s secondary tumours have spread from the original cancer, he is most unlucky. Recurrence after such a long time is unusual, although some secondary cancers do remain hidden away as micrometastases for as long as this, most commonly in malignant melanomas (cancerous moles).

With melanomas, secondaries may become active decades, rather than years, after the primary tumour has been removed. But both breast and prostate cancers can appear years after the primary tumour.

The other possibility is that the reader developed another small primary tumour in his other breast that escaped notice. It is harder to carry out mammography screening on small male breasts than on female breasts.

Unfortunately, our reader knows little about his family history as most of his relatives died in concentration camps. A history of breast cancer on either the male or the female side may be associated with male breast cancer.

Gynaecomastia — when a man has large, female-style breasts — is also a risk factor but our reader’s breasts have always been of normal size.

In 21st-century Britain the most common cause of gynaecomastia is liver failure. When a man suffers some degree of liver inadequacy (excessive alcohol intake is a frequent cause), the female hormones that circulate in every man are inadequately metabolised. The consequent increased amounts of oestrogen result in large, feminine breasts, shrinking genitalia and diminishing secondary sexual characteristics such as body hair. There is also loss of muscle power and a raised risk of breast cancer (our reader, though, drank only in moderation).

Another common cause of gynaecomastia is hormonal treatment for prostate cancer. This has been associated with feminisation but there is no evidence that it increases the likelihood of breast cancer, maybe because men rarely take such hormonal treatment for as long as other men are able to enjoy too much alcohol.

Gynaecomastia may also be a side-effect of taking the indigestion remedy cimetidine, the diuretic spironolactone and, less often, some calcium channel blockers or digitalis. Male users of cannabis or methadone should be aware that they, too, may develop large breasts, as may athletes who take anabolic steroids.

Treatment for male breast cancer is the same as for women and includes Tamoxifen in relevant cases that are hormone-sensitive.

A year ago this month the son of a woman reader returned from Ghana, where he had been doing voluntary work in a school. He appeared to be healthy, happy and full of life, yet two weeks later he died from malaria. His mother has written to The Times and elsewhere to raise awareness of the risk of malaria and the fact that many people, herself included until recently, are unaware of its potential to kill. The boy’s mother asks why such ignorance is so widespread and why people who travel to malarial zones — often youngsters on their gap year — don’t do more to try to prevent it.

There is no single pill that can be guaranteed to prevent malaria, but there are simple prophylactic treatments that reduce greatly the risk of a traveller catching it. A visit to any GP practice or travel clinic will reveal which drugs are needed for each country that the traveller intends to visit.

Although drugs are only part of the preventive measures needed, the importance of correct drug treatment was emphasised by a recent BBC investigation into alternative doctors who put their faith only in homoeopathic remedies, which have been shown to be totally ineffective.

The most important precaution is to avoid being bitten in the first place, if possible. Travel clinics will describe the steps necessary to avoid insect bites, whether the traveller is a backpacker or a managing director. These include having mosquito guards in front of bedroom windows, mosquito nets over beds and, especially in the evenings, wearing long sleeves, trousers and insect repellents.

People should be alert to the danger of being bitten when standing in the shade of trees during the daytime as well as when drinking or chatting outdoors in the evenings or at night. Another essential precaution is to remember to start taking antimalarial tablets at the appropriate time before going overseas, and to continue to take them for the prescribed number of days after returning.

If, despite every effort, a returning traveller becomes ill and is suffering from any untoward symptom, the doctor must be told immediately that the patient has been overseas and has visited a malarial zone.

ASK DR STUTTAFORD

Topic of the week: E-mail Dr Stuttaford your questions on malaria.

Other topics: send your questions to drstuttaford@thetimes.co.uk or to times2, The Times, 1 Pennington Street, London E98 1TT. Please include the following: the symptoms (and how long they have been present), the person’s age, sex and marital status. Dr Stuttaford’s replies cannot apply to individual cases but should be taken in a general context. Readers are always advised to consult their GP, as only he/she will be fully conversant with the background. We regret that Dr Stuttaford cannot enter into personal correspondence.