Cancer Consult India (CCI), based in New Delhi, is a voluntary organization dedicated to cancer prevention and treatment in India. At CCI, a team of highly motivated medical professionals have been actively engaged in cancer control activities. Through the activities of the community, we try to bridge the gap that exists in between the cancer patients, knowledge, research, prevention and treatment in the country. visit our website : https://cancerconsultindia.com/

1. Since 1975 worldwide obesity has tripled.
A 2016 report stated that more than 1.9 billion adults, 18 years and older, are
overweight. Of the 1.9 billion, 650 million were reported to be obese.
The link between obesity & an increase in cancer risk has been observed. In
fact, 1 in 20 cancer cases in the UK is caused by excess weight.
It is beneficial to note that a healthy weight reduces the risk of about 13
different types of cancer.
In India, about 135 million+ individuals are affected by obesity. And with the
advent of socio-economic development in the country, a part of the urban
Indian population falls in the category, putting them at a higher risk of being
diagnosed with cancer.
Correlation between obesity and cancer

2. A multitude of researchers has shown through extensive research that excess
body fat increases the risk of several cancers including colorectal cancer,
postmenopausal breast cancer, uterine cancer, esophageal cancer, kidney
cancer, and pancreatic cancers.
According to experts, obesity-related cancer can be due to inflammation
caused by visceral fat. Visceral fat has large cells, and they are many in the
body protecting vital organs. An obese individual has more visceral fat in their
body, leaving less room for oxygen. This low oxygen triggers inflammation.
Not only that, but excess fat also affects different body processes, including
how certain hormones like insulin and estrogen are managed.
All of this can increase the risk of cancer by indirectly affecting how cells
divide & how they die.
Changes in the populations of immune cells due to diet, & in turn, obesity is
also known to increase the risk of cancer. Obesity can reshape cancer cell
mechanisms impairing T-cells’ inflammatory functions. It remodels cellular fuel
use of tumors, increasing the fatty acid oxidation of cancer cells & reducing
the numbers as well as the spatial positioning of CD8+ cells. This, in turn,
reduces antitumor immunity.
Obesity and cancer treatment
Top cancer doctors and oncology researchers vouch for the fact that lean
cancer patients mostly outlive obese cancer patients. Previously, it was
believed to be only because of obesity itself. But today, cancer specialists are
realizing that bad outcomes can be tied to mistreatment based on individual
requirements. You see, obese patients come with risks that others do not, and
that warrants a different treatment approach.
In this blog, we will discuss the effect of obesity on different cancer
treatments.
 Cancer Surgery
The correlation between obesity & cancer surgery is a mixed bag. In the case
of breast, colorectal, and intra-abdominal cancer, no correlation between BMI
& short-term or long-term mortality along with major surgical complications
has been found. But there is an increased frequency of minor surgical
complications, which might increase costs, reduce the quality of life, & delay
adjuvant therapy. Studies on prostate cancer, on the other hand,
demonstrated prolonged surgical time & greater blood loss in obese patients.

3. The effect of obesity was also correlated with an increased chance of
recurrence, poor outcome, and potential need for different adjuvant
treatments.
 Radiation Therapy
Among prostate cancer patients being administered external beam radiation
therapy, inferior outcomes due to obesity have been noted. External problems
may arise as well; for example, delivering issues, like difficulty with daily set &
increased likelihood of cancer location shifting. Not only that but it has also
been observed that obese cervical cancer patients can even experience an
increased rate of treatment-related toxicity compared to patients in the normal
weight range. In breast cancer patients, cancer doctors have seen that a
larger breast size & higher BMI can be associated with a higher risk of cute or
late dermatitis after radiation.
 Chemotherapy
The dosing of chemotherapy drugs, which is essential in treating cancer, is
calculated using BSA or body surface area in adults. Chemotherapy dosing is
extremely important in treating cancer because it decides efficacy.
Unfortunately, up to 40% of obese patients receive limited chemotherapy
dosing, which does not correlate to their actual body weight. Why? Because of
toxicity concerns among obese patients due to the higher dose of medication
based on their actual body weight.
Also, obese cancer patients often have comorbidities like vascular disease or
diabetes. This increases the chances of peripheral neuropathy. Baseline
peripheral neuropathy is often associated with dose-limiting chemotherapy‐
induced neurotoxicity.
But a low dose of chemotherapy can increase chances of disease recurrence
and mortality, contributing to low survival rates.
 Hormonal Therapy
Endocrine therapy is a common adjuvant treatment for hormone-receptor-
positive breast cancers with appropriate hormone receptors. In patients using
tamoxifen, no correlation was found with obesity and efficacy or recurrence.
But in premenopausal women taking ovarian suppression medication, high
BMI was associated with low efficacy of endocrine therapies inhibiting
aromatase and promoting the production of estrogen, including from adipose
tissue, like anastrozole and goserelin. Aromatase Inhibitors or AI did not give
as good results in obese women as they did in leaner women.
 Immunotherapy & stem cell therapy

4. There is very little information available regarding the efficacy of
immunotherapy or stem cell therapy among cancer patients concerning BMI,
whether normal or higher.
Does obesity hamper cancer treatment – Conclusion
Further research is needed to get a clearer picture of the correlation between
the efficacy of cancer treatment and obesity because there are multiple gaps
in the literature. While most research associated BMI with obesity, BMI cannot
measure the adiposity of a body, which is important for treatment efficacy.
Hence, more research is required in the area. However, the studies conducted
so far have given a clear indication that obesity negatively impacts several
cancer treatments, the bounds of which we are still discovering.
Note
Dr. Manish Singhal is a leading cancer specialist in Delhi NCR. With an acute
understanding of lifestyle choices affecting cancer & cancer treatment, he &
his team have successfully created efficient and customized cancer treatment
plans for patients suffering from obesity and its many associated issues.