The effect of dietary and lifestyle factors on prognosis and quality of life of bladder cancer patients

Bladder cancer is the fourth most common cancer among men and the eighth most
common cancer among women in the Netherlands, with 6,019 men and women
diagnosed in 2010. About 70% of bladder cancer patients present with
non-muscle-invasive bladder cancer (NMIBC). These patients have a relatively
good survival, but are at high risk of tumor recurrence and disease progression
(approximately 60% and 15% within 5 years, respectively). They are therefore
subjected to frequent follow-up by cystoscopy and treatment. This makes bladder
cancer the most expensive cancer in terms of health care expenditures. The
frequent recurrences may also impact greatly on health-related quality of life
(HRQOL). Thus, it is important to identify prognostic factors that may enable
to reduce the risk of frequent recurrence(s) and progression, and improve HRQOL.
Dietary and lifestyle factors may play an important role in bladder cancer
prognosis. A high fluid intake reduces the exposure to carcinogens by diluting
the urine and reducing the contact time through increased frequency of
micturition. Most dietary substances and metabolites are excreted by the
urinary tract, and fruit and vegetables are a rich source of nutrients with
anticancer properties. Smoking is the most important lifestyle factor
associated with bladder cancer, and smoking cessation decreases the risk.
However, there is only sparse data on the association between (changes in)
dietary and lifestyle habits and bladder cancer prognosis and HRQOL. Further,
it is unclear to which degree bladder cancer patients are adhering to dietary
and lifestyle guidelines for cancer survivors, which is an important first step
in promoting healthy lifestyle behavior.
Thus, there is an urgent need to gain insight in the dietary and lifestyle
habits of bladder cancer patients in order to develop effective dietary and
lifestyle interventions to reduce their risk of recurrence/progression and to
improve their HRQOL.

The purpose of this study is to answer the following research questions:
1. What are the dietary and lifestyle habits (with a focus on, but not
restricted to, fluid intake, fruit and vegetable consumption, and smoking) of
NMIBC patients before diagnosis of cancer, do they change these habits after
diagnosis, and to what extent do they adhere to the existing dietary and
lifestyle guidelines for cancer survivors at both time points?
2. Are pre- and postdiagnosis dietary and lifestyle habits, as well as changes
in these habits, associated with the risk of recurrence and progression of
NMIBC?
3. What is the burden imposed by NMIBC upon patient HRQOL, and does this change
during the course of the disease?
4. Are pre- and postdiagnosis dietary and lifestyle habits, as well as changes
in these habits, associated with HRQOL?
5. Are NMIBC patients aware of, do they currently receive, or would they be
interested in receiving information about dietary and lifestyle factors that
may improve their prognosis?

Prospective cohort study. At inclusion shortly after first transurethral
resection, dietary and lifestyle habits before diagnosis as well as HRQOL will
be assessed by questionnaire. At first routine follow-up approximately three
months after transurethral resection, and 15 months after transurethral
resection, changes in dietary and lifestyle habits and HRQOL will be assessed.
At three and 15 months after transurethral resection, blood samples will be
collected in which biomarkers of fruit and vegetable intake will be assessed as
well as cotinine as a compliance marker for smoking cessation in ex-smokers.
Information about therapy, disease characteristics and additional medications
will be derived from medical records and taken into account in the analyses. In
addition, a survey will be conducted to investigate the awareness and the type
of information bladder cancer patients currently receive and/or would like to
receive from their urologist concerning diet and lifestyle.

Risks associated with participation in this cohort are confined to the normal
risks of taking blood samples (risk of fainting and of bruising). Since the
drawing of blood will be done by professionals, risks are low. The only burden
for participants is, that they are asked to fill out questionnaires shortly,
three months, and 15 months after diagnosisabout, and that they are asked to
donate blood samples three and 15 months after diagnosis. Blood collection is
aimed to be at the same time as the regular follow-up appointment in the
hospital.