These are general problems and not found in all cancers but a lot of different cancers. Our goal is not to get specific on any one cancer but give an overall view. Later we will go over specific cancers. Also, these are incurable or malignant cancers.
Patients need to have an understanding of the changes that happen in malignant cancers. Cancer cells in our body produce abnormal substances that change the delicate dynamics of the body’s chemistry. For example, tumor cells can produce substances that change the way hormones react in the body or the way we use our food. Nutritional advice will be given keeping in mind that at this late stage nutrition as we know it has the least effect. Still, some positive effects we will talk about aid the body in weight gain, comfort, and resisting infection.
Weight gain at this point once the patient starts into cachexia – or wasting in studies has not shown to increase survival. It has shown to increase in the perception of quality of life and it may help decrease infection.
Our discussion in this section will center on the cancer with malignancy that hasn’t been cured through surgical resection, chemotherapy, or radiation. All the abnormal body chemical reactions revert back to normal with cure. Remember, it was a tumor cell producing the abnormal body chemical reaction in the first place. A lot of cancer patients estimated between 40-80 percent develop some kind of nutritional deficiency. The cells of the body that divide reproduce or replace rapidly are the ones most susceptible. The skin, hair, intestine, and blood cells replace themselves from one day to around three months. Deficiencies in nutrient problems show up first in these areas. In hospitals, weight loss is one of the most reliable indicators of the cancer patient’s health. It still is considered one of the best indicators of a cancer patient’s health and survival status.
Weight loss is also associated with increase in infection. Tumors secrete substances one of which is called cytokinines that cause an abnormal weight loss. The weight loss associated with cancer is called cachexia or wasting of the body. Cachexia in cancer is different than cachexia in starvation in several ways. In starvation, the body conserves its energy the REE or resting energy expenditure is lowered. Protein is very important to the body, making up the organs and enzymes needed to maintain life. So the body always tries to hold on to its protein stores and uses this as an energy source last in starvation. On the other hand, one study in long-standing cancer patients showed an increase in resting energy expenditures in 26 percent of patients, normal in 41 percent, and decreased in 33 percent. What is happening is the tumor produces substances that alters the way our bodies use carbohydrates, fats, and proteins.
General cancer patients have a negative nitrogen balance or use too much protein, the opposite of starvation. Normally our protein stores are maintained by our body’s pool of amino acids or proteins. The body has a very shallow pool of amino acids of only about six percent. Once these are used up, they have to break down their own bodies for protein.
There are several ways of measuring protein breakdown. One is in the urine. There are several markers in the urine indicating protein breakdown and muscle wasting. These can be monitored. They include creatinine and nitrogen. These give an estimate of muscle breakdown and can be measured in the amounts in urine. Check with your physician on some of these lab tests.
Strength can help determine protein loss in cancer patients. Protein loss in cancer patients can occur despite normal protein intake. One protein deserves special mention call albumin. Albumin carries many important enzymes and hormones throughout the body. It also maintains 76 percent of the fluid balance between our tissues and the fluid in our vascular system. Albumin is made up of 584 amino acids so it is used to monitor protein breakdown in the hospital every three to four days. Albumin in the hospital setting is used as a prediction of survival. Forty percent of albumin is in our circulatory system, while 20 percent is in our skin.
Some studies have shown that increasing protein intake to 1 to 1.5 grams per kilogram of weight or 300 kilocalories of amino acids stimulated albumin synthesis for construction. In one study, increase in the amino acids lucine, isolucine, valine increased production from 100 milligrams per kilogram a day to 190 milligrams per kilogram per day.
Growth hormone has been reported to improve nitrogen balance in early cancer stages. Testosterone may also cause an increase in skeletal muscle. All these should be discussed with your physician as testosterone and growth hormones is thought to stimulate some tumors.
Serum albumin levels are able to predict mortality in some late-stage cancer patients. Decreased levels of the amino acid pool and severity of the cancer are the two biggest factors in albumin levels. In malignant cancers, the tumors also secrete substances or enzymes that reduce the use of carbohydrates. This means that the sugar or glucose in our blood goes unused. The body normally secretes insulin from the pancreas to move blood sugar or glucose into our muscles and liver. However, in cancer patients, the body doesn’t respond to insulin. This is very similar to insulin-dependent diabetes mellitus except that by giving more insulin doesn’t really help. Also, high insulin levels depress the immunity, not what you need in cancer patients. Insulin resistance also usually precedes the weight loss. Thyroid levels can also be decreased in cancer patients and can lead to further ineffective insulin use.
The breakdown of fats for energy is also used, and it is thought that tumors may secrete a fat mobilizer. Fat, especially the N-6 polyunsaturated fatty acids have shown to stimulate tumors and should be switched to N-3 polyunsaturated fatty acids. Early studies indicate these to have inhibitory effects on tumors. Twenty percent of calories should come from fat, a significant drop from the normal American diet of 34 percent and below the RDA of 30 percent. Protein should replace the lost calories from fat.
Many patients have anemia and can be treated with iron. If there is chronic infection, this could flair up other factors and should be discussed with your physician. Vitamin C, zinc, and copper have reported benefits in normal healing and infection and can be tried. These nutrients have been observed to be deficient in many cancer patients. One study showed less infections with a multivitamin-mineral supplement.
A lot of cancer patients have an aversion to food and get nausea when eating after chemotherapy. Studies show that you should avoid your favorite food on days of chemotherapy. A history with an accurate measurement of weight is vital to following these patients. Some drugs cause increase in fluid retention and a false impression of a stable weight. A five percent decrease in weight is significant. These suggestions are not cures but can make small changes. You should always talk to your doctor as every patient and cancer is different.