Healthy Living After A Breast Cancer Diagnosis

Healthy Living After A Breast Cancer

Diagnosis

Jennifer Ligibel, MD

Dana-Farber Cancer Institute

Young Women’s Forum

October 13, 2017

Research increasingly shows that “energy balance” is important in breast cancer

Energy we take in Energy we “spend” What remains

(Food) (Exercise + Metabolism) (Weight)

_=

Each of these factors has been linked to breast cancer

But diet and exercise recommendations for

preventing and treating cancer are everywhere–

and they don’t always agree!

How can you sort out fact from fiction?

Is there an optimal diet to prevent

breast cancer recurrence?

Is exercise important for breast cancer

survivors?

Most studies looking at links between diet

and cancer are “Observational” studies

• In this kind of study, a large group of people is asked what kind

of food they are eating

• Participants are followed over time (“Observed”) to see who gets

cancer or has a recurrence, and links are made between cancer

and the kinds of diet people consumed

Pro

Studies many different

diet factors and cancers

at once

Con

Hard to separate out other

factors (people who eat

certain types of diets may be

different in other ways, like

exercise more or weigh less)

What kinds of foods have been linked to

cancer risk?

• Red meat has been linked to colon

cancer risk

– Try to consume < 18 ounces/week

• Smoked and processed meats have

been linked to stomach and other

cancers

– Even small amounts linked to slight increase

in cancer risk

• Alcohol has been linked to risk of

head and neck, liver, esophageal and

breast cancers

– Women should consume no more than 1 drink

day; men no more than 2

Do we have any evidence that

changing diet could prevent

breast cancer?

One study looked at whether eating a

Mediterranean diet affected the risk of

developing breast cancer

Mediterranean diet:

• Lots of veggies, fish,

olive oil

• Not much red meat or

processed food

• A little wine

Study basics

• Primary goal: study the effect of a Mediterranean diet on heart

disease

• Study also looked at effect of the diet on risk of breast cancer in

women taking part in the study

• Study participants divided into 3 groups• Mediterranean diet + extra virgin olive oil

• Mediterranean diet + nuts

• Usual diet

• About 4000 women who had never had breast cancer took part

Did the diets make a difference?

• Not very many women developed breast

cancer—only 35 during the course of the

study

• Women in the olive oil group had a 62% lower

risk of breast cancer compared to usual diet

group

• Women in the nut group had a 38% lower risk

of breast cancer compared to usual diet group

Is there any evidence that a

specific diet or food has health

benefits for women who have

already had breast cancer?

“Observing” trials show links between some

types of food and breast cancer recurrence

• Diets high in fat linked to

higher cancer recurrence

• Weak links between

higher intake of fiber and

protein and lower cancer

recurrence

• No real link with

carbohydrate intake

Most studies looking at the direct

effect of a particular food on

cancer were done using cells in

test tubes or in animals, not people

Broccoli and Breast Cancer

What’s the Evidence?

• Different kinds of breast cancer cells

were grown in a lab

• Breast cancer cells were exposed to

different concentrations of nutrients

isolated from broccoli

• At high concentrations, the growth rate

of breast cancer cells slowed and cells

had a higher death rate

Broccoli in rats

• Young female rats divided into groups; some given 5 days of

nutrients isolated from broccoli, some given typical food and no

broccoli

• All rats exposed to chemical that

causes breast cancer

• Rats given high doses of broccoli

nutrients about 50% less likely to

develop breast cancer

What about in people?

• No studies testing what happens in women with breast

cancer who increase broccoli in their diet

• Several studies asked women without breast cancer

how much broccoli (and other fruits and vegetables

they ate)

• Results not very consistent

• Some studies showed a slightly lower rate of breast

cancer in women who ate more broccoli

• Other studies showed no difference

But is there any evidence that diet

after breast cancer is linked to risk

of cancer recurrence?

Two studies looked at whether changing diet

after diagnosis would lower risk of recurrence

Women’s Interventional Nutrition Study (WINS)

• Goal: test the effect of

reducing dietary fat after

breast cancer diagnosis on

recurrence

• Study enrolled ~2400 women

with Stage I-III breast cancer

• WINS Diet : reduce fat to

15% of total calories

.

Second trial testing effect of changing diet on

breast cancer recurrence

• Goal: to test the effect of eating

less fat, and more fruits,

vegetables and fiber on the risk

of breast cancer recurrence

• Included 3088 women with

stage I-III breast cancer

Women’s Healthy Eating and Living (WHEL) Trial

Both trials successfully changed

participants’ diets

WINS Trial

• Low fat diet group cut fat by

33%

• Usual diet group cut fat by

9%

WHEL Trial

• Diet group

– Cut fat by 25%

– Increased fruits and vegetables

by 5 servings per day

• Usual diet group

– Decreased fat by 4%

– No change in fruits and

vegetable servings

Results of trials were a bit different

WINS Trial

• Low fat diet group had a

reduced risk of breast cancer

recurrence

• Benefit mostly in patients with

estrogen negative cancers

• Benefits seemed to be

reduced over time

WHEL Trial

• No difference in recurrence

risk in diet and usual care

groups

• No benefits of diet program

seen in any patient group

No clear evidence that a

specific diet can reduce or

increase the risk of breast

cancer recurrence, based on

what we know now

What about exercise?

• Women who exercise less

likely to get breast cancer

• A few studies have looked at

links between exercise after

breast cancer diagnosis and

risk of recurrence

• Exercise linked to 30-50%

lower risk of cancer

recurrence!

What kind of exercise were these women

doing?

• The most common exercise was walking at a moderate pace

• Benefits seen with walking at a 3-mile-per-hour pace for half an hour per day

• Not necessary to run a marathon! (of course you always can if you like)

Exercise also shown to have other

benefits in breast cancer survivors

• Better quality of life

• More energy

• Less arthritis and joint pain

• Better self esteem and mood

• Plus:

decreased risk of diabetes and heart disease!

How could exercise effect breast cancer?

• Enrolled breast cancer survivors

who were not exercising

• Assigned them to exercise or

usual care group

• Exercise program:

– Strength training

– Cardio at home

• Study showed that exercise

lowered levels of insulin, a

hormone linked to breast cancer

The Dana-Farber Exercise and Insulin Study

The Breast Cancer Weight Loss Trial

BWEL Study Basics

• The BWEL study will test the ability of a weight loss program to

reduce rates of breast cancer recurrence

• BWEL is a randomized trial: half of the study participants will

take part in the weight loss program and half will receive a

breast cancer education program

• The study will enroll 3136 women in the US and Canada

• Study is designed to test whether weight loss reduces the risk of

cancer recurrence by 20%

Who can take part in BWEL?

• Women with breast cancer diagnosed within the past year

• Must have a BMI of at least 27kg/m2

• Must have HER-2 negative breast cancer

• Cancer must be stage II or III

• Patients can’t have metastatic breast cancer

• Patients can’t be taking certain types of diabetes medicines

• Must be completed with surgery and with chemotherapy (if it

was used)

BWEL Weight Loss Program

• Goal: to help participants lose

10% of their body weight

through diet and exercise

• Participants are paired with a

health coach

• Receive 42 phone calls over

2 years

• Record weight, food intake

and exercise

Conclusions

• Exercise, weight and diet are

important in breast cancer

patients

• It’s never too late to make healthy

changes in lifestyle!

• More research is needed to

understand how changes in diet

and exercise could affect breast

cancer recurrence rates