Transcript Head and Neck Cancer - MAPA (Mid

The Epidemiology of
Head and Neck Cancer
Scott Langevin, MHA CT(ASCP)
Doctoral Candidate
June 5, 2009
Anatomy of the Upper Aerodigestive Tract
(UADT)
• Head & neck cancer
refers to cancers of
the UADT:
–
–
–
–
–
–
–
Oral Cavity
Pharynx
Hypopharynx
Larynx
Nasopharynx
Nasal cavity
Paranasal sinuses
Source: http://utahhealthsciences.net/customer/image_gallery/332/ENT_drawing.jpg
Epidemiology
• Head and neck cancer in the US, 2008:
– 47,560 new cases (3.3% of US cancers)
– 9th most common cancer
– 11,260 deaths (2% of US cancer deaths)
– 14th most common cause of cancer death
• Globally, head and neck cancer results in:
– 563,826 new cases (5.2% of world cancers)
– 301,408 deaths (4.5% of world cancer deaths
Survival
• 60% overall 5-year survival
– Virtually unchanged over past 3 decades
– Varies by site
Percent 5-Year Survival
Site
Lip
Oral Cavity
Oropharynx
Hypopharynx
Larynx
Overall
85.6
56.7
50.6
33.3
62.0
Local
89.6
72.0
61.0
56.0
74.3
Regional
82.7
43.8
50.6
34.6
53.2
Distant
40.0
35.2
30.2
12.9
38.3
Source: Carvalho et al. Trends in incidence and prognosis for head and neck cancer in the United States: a site specific analysis of
the SEER database. 2005.
Stage at diagnosis by site
90.0
80.0
70.0
Local
60.0
Regional
50.0
Distant
40.0
30.0
20.0
10.0
Larynx
Hypopharynx
Oropharynx
Oral Cavity
Lip
0.0
Common Types of Head & Neck Cancer
• Head and neck cancer is a heterogeneous
category of malignancies
• 90-93% are head and neck squamous cell
carcinomas (SCCHN)
• 3-6% are nasopharyngeal carcinomas (NPC)
• 1-3% are salivary cancers
Squamous Cell Carcinoma of the
Head and Neck (SCCHN)
Clinical Presentation & Treatment
• Currently no proven screening method except
visual examination
• Symptoms: hoarseness, dysphagia, odynophagia,
ulcerations, bleeding
• 1st line treatment modalities:
– Early stage: surgery (preferred) or radiation
– Advanced stage: typically surgery + chemoradiation
• Currently Cisplatin is treatment of choice, alone or in
combination
• EGFR inhibitors are in trials (cetuximab)
Epidemiology
• 93% of head and neck cancers are SCCHN
• Median age at diagnosis = 62 years
– Although, incidence in adults < 45 increasing
• Particularly for base of tongue and tonsillar SCC
• Men are 2.78 times as likely to develop SCCHN
– 2.59 times as likely to die from it
• Higher incidence in African-Americans
– Poorer 5-year survival (16-20% lower)
Prognostic Indicators
• TNM stage (higher = worse)
• Cervical nodal involvement is one of the strongest
predictors (50% reduction in survival)
– 2/3 SCCHN patients present with cervical mets
– 10% present with distant mets
– Extracapsular spread (ECS) further reduces survival
• Other predictors
–
–
–
–
–
Nodal burden
Perineural invasion
Histologic grade
Extent of necrosis
Positive tumor margins
Recurrence and Second Primaries
• > 50% of patients with locally advanced
SCCHN experience recurrence within 2 years
• 2nd primaries occur in 15% of SCCHN patients
at a rate of 3-5% per year
• Tumor recurrence or development of a second
primary is a major reason for treatment failure
and adversely impacts long-term survival
Tobacco
• IARC classifies cigarette smoking as a Group 1
carcinogen and a causal factor for SCCHN
• Linear dose-response for smoking & SCCHN
– Duration > intensity, although both matter
– 3- to 10-fold increase in risk for smokers vs. nonsmokers
– 5- to 25-fold increase in risk for heavy smokers vs nonsmokers
• Other forms of tobacco are also associated with
SCCHN (pipe, cigar, chew)
• Tobacco use also associated with 2nd primary
SCCHN
Source: Sturgis et al. Cancer. 2007. 110(7): 1429-35
Carcinogenic Effect of Tobacco
• > 60 carcinogens identified in tobacco smoke
• Polycyclic aromatic hydrocarbons (PAH) are
most potent in burnt tobacco
• Nitrosamines and their metabolites are most
potent in smokeless tobacco
• Main effect is via DNA adduct formation ->
mutations
Alcohol (EtOH)
• IARC classifies consumption of alcoholic
beverages as causal for SCCHN
• Contributive factor in ~75% of SCCHN
• Dose-response effect
– 50 g EtOH/day is associated w/ 2- to 3-fold
increased risk relative to non-drinkers
– Heavy drinkers (> 100 g/day) = 4- to 6.5-fold
increase compared w/ non-drinkers
• Also associated w/ 2nd primary SCCHN
Carcinogenic Effect of EtOH
• Main effect derived from acetaldehyde, the
primary metabolite
– Forms DNA adducts and interferes w/ DNA
synthesis and repair
– High levels of acetaldehyde in saliva of alcoholics
w/ SCCHN
• EtOH metabolized by bacterial enzymes
– Poor oral health = increased acetaldehyde levels
Cigarette & EtOH Synergy
• There is an interaction between EtOH and
smoking, as it relates to SCCHN
– The combined effect is multiplicative of the
individual effects alone
• Combined use accounts for 73% of SCCHN
• EtOH acts as a solvent for tobacco carcinogens
• Smoking results in a shift in oral flora leading
to increased acetaldehyde concentrations
Human Papillomavirus (HPV)
• 25% of SCCHN associated w/ HPV
– 45-60% of oropharyngeal tumors, especially palatine
and lingual tonsils
• In contrast, 10% HPV+ in normal OP mucosa
• 90-95% of HPV+ tumors are HPV16+
• HPV positive tumors represent a distinct clinical
subset of tumors
– Patients are younger, less likely to smoke/drink
– Tumors are more likely basaloid and poorly diff
– Better prognosis
HPV Oncogenic Effect
• Primarily stems from action of E6 & E7 viral
oncoproteins
– E6 binds and inactivates p53 tumor suppressor
• Loss of p53 mediated apoptosis
– E7 binds and inactivates pRb tumor suppressor
• Loss of G1-S phase checkpoint
• p16 overexpression is a surrogate marker for
HPV-mediated SCCHN
Other Risk Factors
• Environmental/Occupational
– Indoor air pollution
• Wood smoke or heating/cooking with fossil fuels
– Chronic second-hand tobacco smoke exposure
• 1.5- to 5-fold increase in risk
– Metal working
– Exposure to toxins during mustard gas production
• Diet
– High in animal fat, low in fruits and vegetables associated
w/ increased risk of SCCHN
– Low folate intake may also be associated
• Gastroesophageal reflux
Field Cancerization
• The epithelium is chronically exposed to environmental
carcinogens
– Particularly true of smokers/drinkers
• Mutations that confer a growth/survival advantage are
clonally selected
– Gradually replace normal epithelium
– New mutations occur within these fields giving rise to
subclones; eventually can become malignant
– Can give rise to distinct but clonally related tumors
– Evidenced by mutations/alterations in “negative” margins
• This helps explain high recurrence/second primary rate
of SCCHN
Nasopharyngeal Carcinoma
(NPC)
Nasopharyngeal Carcinoma (NPC)
• Arise from the epithelial lining of the nasal
cavity/nasopharynx
• Results from the interplay of environmental,
genetic and viral risk factors
• 70-75% present with ear & nasal symptoms
• 75% present with painless, enlarged cervical
nodes
Treatment
• Radiation or chemoradiation is typically the 1st
line of therapy
– NPC is radiosensitive
– Difficult to operate on nasopharynx
• thus surgery is not generally used as 1st line therapy for
primary tumor
– Surgery is used to remove cervical nodes with
metastatic disease
NPC Classification
• WHO classifies NPC into 3 types:
1. Keratinizing SCC (type I)
1.
•
•
Believed to be of a distinct etiology from types II & III
Dominant type in low incident regions
39.4% of US NPC
2. Non-keratinizing SCC (type II)
•
•
5% of high-incident regions
25.0% of US NPC
3. Undifferentiated SCC (type III)
•
•
95% of high incident regions
14.0% of US NPC
* 21.6% of US NPC are diagnosed as Carcinoma, NOS
Incidence & Mortality
• 80,000 cases with 50,000 deaths annually
– < 1 per 100,000/year incidence
– 23rd most common cancer in the world
• 2-3 fold higher risk for males:females
• Broad racial/ethnic and geographic variation
– 4th most common cancer in Hong Kong
• Highest incidence in Asian, N African/Mid east,
and Arctic populations
Migrant Studies
• After migration, risk remains high
– Chinese in US have 10-20 fold increased risk
compared to US Whites and Blacks
– However, Chinese immigrants have ½ the risk of
their counterparts in China
– Conversely, Whites born in China or Philippines
have an increased risk for NPC compared with US
• Suggests both environmental and genetic
components
NPC Incidence and Age
US incidence by age
• Monotonic increase with age
• Secondary peak from 55-59 yo
Hong Kong incidence by age
• Peak age at 50-59 yo
Source: Chang et al. Cancer Epidemiol Biomarkers
Prev. 2008;15(10):1765-77
NPC Prognosis
• Overall 5-year survival of 65% (US)
– Local: 80-90%
– Regional: 50-70%
– Advanced: poor
• Varies by type:
– Undifferentiated (type III) has best prognosis due
to high radiosensitivity
– Keratinizing (type I) have worst prognosis
• more radioresistant
Epstein-Barr Virus (EBV) & NPC
• Member of the herpesvirus family
• Transmitted chiefly via saliva
• Primarily targets B lymphocytes but also
infects oropharyngeal tissue
• EBV DNA detected in ~100% of type II and III
NPC
– Type I is not as consistent
– Also detected in NP dysplasia
EBV Prevalence
• > 90% of the world population is EBV seropositive
(mostly latent infection)
• Geographic variability in when infection occurs
– Hong Kong:
• 80% of kids infected by age 6
• ~100% by age 10
– US:
• 50% of kids infected by age 5
• 95% of adults infected by age 40
• Tends to occur earlier in developing countries
– Likely due to crowding and less hygienic conditions
• 30-50% adults develop mononucleosis after primary
infection
– Usually latent in children
EBV & NPC
• Early-life EBV infection increases risk
• EBV appears to be a necessary but insufficient cause of
cancer
– Most people are infected; only a small minority get the
disease
• EBV most likely interacts with genetic and
environmental risk factors in NP carcinogenesis
Environment
EBV
Genetics
NPC
Salt-Preserved Fish & Meat
• Strongest non-viral risk factor (especially fish)
• Associated with type II & III
– Weekly consumption: 1.4-3.2 fold increased risk
– Daily consumption: 1.8-7.5 fold increased risk
• Childhood exposure increases risk > adult
– Traditional weaning food in China
• Salt is an ineffective preservative
– Partial putrification
– Contains:
•
•
•
•
Nitrosamines (also found in tobacco)
Bacterial mutagens
Genotoxins
EBV reactivating compounds
Smoking
• 2-6 fold increased risk of NPC
– Particularly true for Type I
– 2/3 of Type I attributable to smoking
• IARC classifies smoking as a Group I
carcinogen
– Sufficient causal evidence for NPC
Occupational Exposures
• Nasal cavity is the primary initial site of fume
exposure
• Difficult to study due to (relatively) rare exposures
• Occupational exposures associated with NPC:
– Formalin
• 2-4 fold increase in risk
• Although not consistent across all studies
• Supported by evidence from animal studies
– Heat/combustion exposures
– Wood dust
– Chlorophenols
Other Risk Factors
• Fruit & vegetable consumption (protective)
• Prior hx of chronic ENT or respiratory infection
– 2-fold increase in risk
• Family hx of NPC
– 4-10 fold increased risk for 1st degree relative hx
• Some HLA and xenobiotic metabolism alleles
have been associated with NPC
Salivary Gland Cancers
Salivary Gland Cancers
• 1-3% of head and neck cancers
• Incidence: 2 per 100,000 people/yr
– Incidence is rising in US
• Mean age is 64 yo
– 2/3 occur in people > 55, although occur at all ages
• Heterogeneous group of malignancies
– WHO lists 18 histologies
Site of Origin
• Major salivary glands: 95% of cancers
– 80% occur in the parotid
• 20% of parotid tumors are malignant
– 10% occur in the submandibular gland
• > 50% are of submandibular tumors are malignant
– 5% occur in the sublingual glands
• > 50% of sublingual tumors are malignant
• Minor salivary glands
– Cancers mostly occur in the oral cavity, nasopharynx
or nasal cavity
Clinical Presentation & Treatment
• Present as fixed, painless lumps or swelling,
with trismus, or facial nerve weakness
– May present with or without lymphadenopathy
• Surgery is the primary treatment modality
– May be combined with radiation
• Stage and grade correlate well with prognosis
• After primary treatment, 50% experience
local, regional, or distant mets
5-year Survival by Stage at Diagnosis
100%
96%
90%
77%
80%
73%
70%
60%
50%
37%
40%
30%
20%
10%
0%
I
II
III
IV
Salivary Gland Cancers
• Major risk factors:
– Radiation
– Mixed results for occupational exposures
• Because it is relatively rare, there are few
epidemiologic studies available with adequate
statistical power to identify associations
Mucoepidermoid Carcinoma (MEC)
•
•
•
•
Most common: 30-35% of salivary tumors
Usually involves major salivary glands
3:2 female:male ratio
Mean age of diagnosis is in 5th decade
– Occurs at all ages
– Most common salivary malignancy in children
MEC Prognosis
• 30-70% present with nodal involvement
• 10-20% present with distant mets
• Grade correlates well with prognosis
– High grade: < 50% 5-year survival
– Low grade: 95% 5-year survival
• Recurrences are mostly locoregional but can
metastasize (lung, bone)
Adenoid Cystic Carcinoma (ACC)
• 2nd most common salivary cancer
• Occurs in both major and minor glands
– Most common minor salivary malignancy
• 3:2 female:male ratio
• 4th – 6th decade is the peak occurance
– But occurs at all ages
ACC Prognosis
• Patients initially do well but do poorly long term
– 5-year survival = 89%
– 15 year survival = 40%
• Local control w/ surgery & radiation = 85%
• Tends to recur up to several years later as
systemic mets
– 30-50% experience distant mets
– Rarely mets to regional lymph nodes
• Often associated with perineural invasion
Adenocarcinomas
• Acinic cell carcinoma
– Most occur in the parotid
– Generally slow growing
– Usually low grade but depth of invasion into
adjacent tissue is a better predictor of prognosis
• Polymorphous low-grade adenocarcinoma
– Occurs in minor glands; good prognosis
• Adenocarcinoma, NOS
– Poor 5-year survival (< 50%)
Rare Adenocarcinomas
• Typically low grade (good prognosis):
– Basal cell adenocarcinoma
– Clear cell adenocarcinoma
– Cystadenocarcinoma
– Sebaceous adenocarcinoma
– Mucinous adenocarcinoma
• Typically high grade (poor prognosis)
– Oncocytic adenocarcinoma
– Salivary duct carcinoma
Malignant Mixed Tumors
• Tend to occur in the major glands
• Prognosis depends upon grade
1. Carcinoma ex pleomorphic adenoma
– Account for the majority of MMTs
2. Carcinosarcomas
3. Metastasizing mixed tumor
very, very rare
Other Salivary Malignancies
• Squamous cell carcinoma
• Epithelial-myoepithelial carcinoma
• Anaplastic small cell
– Minor glands; quick growing
• Undifferentiated carcinoma (poor outcome)
– Large cell undifferentiated
– Lymphoepithelial carcinoma
• Higher incidence in Inuits
Questions