epidemiology in the name of god. m zargham md isfahan university mc
TRANSCRIPT
Epidemiology
in the Name of GOD
UROTHELIAL TUMORSEPIDEMIOLOGY: OF THE BLADDER
M Zargham MDIsfahan University MC
Global Burden of Bladder Cancer
Bladder cancer is the 9th most common cancer worldwide, with 357,000 cases recorded in 2002
Bladder cancer is the 13th most common
cause of death, accounting for 145,000 deaths worldwide
(Ferlayet al, 2007; Parkin, 2008.)
There is a geographic difference
in bladder cancer incidence rates
across the world with the highest
occurring in Southern and
Eastern Europe parts of Africa,
the Middle East, and North
America
and the lowest occurring in Asia
and underdeveloped
areas in
Africa
Incidence
The incidence and prevalencerates increase with age, peaking
in the 8th decade of life,and there is a strong association
between environmentaltoxins and urothelial cancer
formation( Jemal et al, 2008;Parkin, 2008.)
incidence
Unfortunately, the incidence rate is rising the
fastest in underdeveloped countries where industrialization has
There has been a 5% decrease in bladder cancer mortality from
1990 to 2004 despite a continued rise in the incidence of
the disease.
Incidence of genitourinary cancers in the Islamic Republic of Iran:
The prevalences ofurological cancers were as follows:
bladder cancer 48.3%; prostate cancer 33.4%renal cell carcinoma 10.3%; renal pelvis and
ureter cancer 0.75%; testicularcancer 6.15%; penile cancer 0.15%; urethral
cancer 0.45%
Akbari ME, Hosseini SJ, Rezaee A,... Asian Pac J Cancer Prev. 2008 Oct-Dec;9(4):549-52
Gender
Bladder cancer is 3 times more common in men than in women
The median age of bladder cancer diagnosis is 70 years of age for men and women, and the incidence and
mortalityfrom the disease increases with age .
incidence rate
The incidence rate of bladder cancer is decreasing faster in men than in women because of the recent decrease in the
percent of men smoking compared with women.
Etiology
Bladder cancer is caused by genetic abnormalities and external risk factors, including carcinogen exposure, nutritional factors, fluid
intake, alcohol, inflammation, infection, chemotherapy, radiation,
and possibly artificial sweeteners.
Genetic:
The null GSTM1 and slow NAT-2 lead to high levels of 3-aminobiphenyl and higher
risk of bladder cancer .These polymorphisms are
present in27% of white, 15% of African-
American, and 3% of Asian males.
External Risk Factors
Environmental Risk Factors
In addition to the skin and lungs, the bladder is the main internal
organ affected by occupational carcinogens. The primary culprits
are the aromatic amines that bind to DNA
( Delclos and Lerner, 2008; Reulen et al, 2008.)
Agriculture workers having the lowest and rubber workers the highest risk of bladder cancer formation.
Environmental carcinogens can enter the system and cause bladder cancer from inhalation or through skin absorption. In general, there is a long latency period of 10 to 20 year.
Smoking
Tobacco is the main known cause for urothelial cancer formation,particularly cigarette smoking, accounts for 60% and 30% of all urothelial cancers in males and females, respectively
Smoking
Overall there is a 2- to 6-times greater chance of developing urothelial cancer with smoking, and the intensity and duration of smoking is linearly related to the
increased risk, with no clear plateau level
(Brennan et al,2000; Smoke, 2004; Boffetta, 2008.)
Prominent bladder cancer risk factors in Iran.
Among life style factors ,cigarette smoking
opium use history of excessive analgesic use and
hair dye use had significant correlations with BC
Asian Pac J Cancer Prev. 2010;11(3):601-Shakhssalim N, Hosseini SY, Basiri A, Eshrati B,…
UNRC.
Opium consumption and risk of bladder cancer: A case-control analysis
Heavy smokers with the opium consumptionexhibited a 6-fold elevated risk for BC
When stratified according to different grades of BC, a 3.4-fold increased risk was associated with the opium consumption in grade III
Hosseini SY, Safarinejad MR, Amini E, Urol Oncol. 2010 Nov- Epub 2008 Dec 25 Dec
A diet rich in fruits and vegetables is protective against bladder cancer formation.
However, even if not directly causative,
there is a very clear association between a healthy diet and a decreased risk of urothelial cancer formation.
Fluid Intake
A meta-analysis concluded that approximately
50% of the studies on fluid intake and bladder cancer risk showed
an association and 50% did not find an
association (Brinkman andZeegers, 2008.)
Alcohol?
However, a meta-analysis of available literature from the last 20 years did not show an association between alcohol intake
and bladder cancer, with a relative risk of 1.2 overall—1.3 in men and 1.0 in womenAnalgesic Abuse/ Artificial Sweeterners
Bacterial infection.
Several investigators have suggested that chronic bacterial
infections may play a role in bladder cancer formation
National Bladder Cancer Study Group reported a 4.8 relative risk (CI, 1.9 to 11.5) of bladder cancer formation for subjects with greater than or equal to three urinary tract infections versus none
(Kantor et al, 1984 .)
InflammaInflammation/Infectiontion/InfectionInflammation/Infection
Infection is clearly a contributor to the formation of squamous
cell carcinoma in patients chronically infected with Schistosoma hematobium and will be covered in the section on squamous cell
carcinoma of the bladder
(Abol-Enein, 2008.)
Inflammation/Infection
Radiation
Interestingly, urothelial cancerformation after radiation is not
age related, but the latency period is 15 to 30 years. Further support that radiation can cause bladder cancer is an increased risk
of urothelial cancer in those patients with prostate or cervical cancer who were treated with radiation therapy
Chemotherapy
Theonly chemotherapeutic agent
that has been proven to cause bladder cancer is cyclophosphamide,
Nilsson and Ullen, 2008
Heredity
First-degree relatives of patients with bladder cancer have a twofold increased risk of developing urothelial cancer themselves, but high-risk of urothelial cancer families are relatively rare
(Aben et al, 2002; Murta-
Nascimento et al, 2007; Kiemeney, 2008
hereditary
There is a component to bladder cancer formation,probably through low-penetrance genes (NAT-2 and the GSTM1 polymorphisms) that increase the susceptibility
of carcinogens.