DEAR DR. ROACH: I had non-Hodgkin’s lymphoma a couple of years ago. I am in remission now, but I never knew what caused it. Is it hereditary, or due to infection? I was told I had hypercalcemia at the time. Could the hypercalcemia have caused the cancer?

Also, I was treated with chemotherapy, called ICE (ifosfamide, carboplatin, etoposide). I felt these drugs caused me to lose my mind temporarily, so I had to stop them. — C.W.

ANSWER: Non-Hodgkin’s lymphoma is a type of blood cell cancer. Nobody knows exactly what causes it, but it pretty clearly comes from damage to the DNA in a precursor blood cell. It does not typically run in families.

High blood calcium levels are common in many cancers. There are several reasons the calcium can be elevated in people with cancer, but the most common are: cancer spreading to the bone and releasing bone calcium through tissue destruction; increased amounts of vitamin D sometimes produced by tumors; and an abnormal protein called PTH-related peptide, which increases both calcium absorption and release of calcium by bone. PTH-related hormone probably is the most likely mechanism in NHL. It’s important to stress that the high blood calcium is a result of the cancer, not a cause of it.

Ifosfamide frequently (10 percent to 30 percent of the time) causes toxicity to the brain, and temporary confusion is one of the most important symptoms. Stopping the ifosfamide temporarily is sometimes necessary, and symptoms usually resolve within a few days.

I am glad your treatment was effective in treating your cancer, but disappointed that you didn’t get your questions answered at the time.

DEAR DR. ROACH: I am a 67-year old woman with Type 2 diabetes. I take 1,000 milligrams of metformin twice a day. My last A1C was 8.1. I desperately want to lose weight to get rid of the diabetes or at least lower the A1C, and am cutting down on carbs, but I am told it is very difficult to lose weight on diabetes meds. Can you explain why, and offer any advice to help me lose weight? Thank you. —R.P.

ANSWER: It can be harder to lose weight with Type 2 diabetes. The underlying defect is resistance to insulin, so blood insulin levels usually are high. Insulin is a growth hormone, a signal in the body that there is plenty of sugar and that the body should store energy as fat.

Medications for Type 2 diabetes that increase insulin levels tend to make it even more difficult to lose weight. Insulin itself, and medications that tell the pancreas to make more insulin, such as glyburide, tend to promote weight gain.

On the other hand, medicines that reduce insulin levels tend to promote weight loss. Metformin works mostly by preventing the liver from making sugar, so the body’s own insulin can work more effectively on the sugar we take in through food. Another medicine, exenatide (Byetta), promotes weight loss in some people. Other medications for Type 2 diabetes have variable effects on weight.

Of course, controlling total calorie intake, especially carbohydrate intake, has a powerful effect on weight, both directly and indirectly. Similarly, exercise makes insulin work better, so modest changes in diet and exercise, along with careful attention to the choice of diabetes medication, can help promote weight loss. I have found that exercising a half-hour or so after eating seems to work well.

Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to ToYourGoodHealth@med.cornell.edu or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475. Health newsletters may be ordered from www.rbmamall.com.