hpv-kling2ALAN KLING, M.D

Dr. Alan Kling is recognized as one of the foremost specialists in the field of HPV infections. Throughout his years as an HPV specialist, Dr. Kling has contributed to research and lectured at various medical schools, including Columbia, Cornell, Mount Sinai, NYU, and Yale as well as having been a part of a number of national panels on HPV and HPV prevention. His extensive research has allowed him to keep up with the latest HPV treatment protocols and to educate others in the field as well. While HPV is an important field of dermatological study for many physicians, Dr. Kling has clearly separated himself from the pack, making him the top HPV treatment specialist in NYC today.

Dr. Kling's private practice offices are located at his Park Avenue practice on the Upper East Side and in Park Slope, Brooklyn.


Q:  What are anal warts?
A:   Anal warts are growths that occur on the skin outside the anus, on the anus, and/or extend into the anal canal. They are caused by an HPV infection, the same infection which causes genital warts.

Q:  What are the symptoms of anal warts
A: People may notice  or feel a bump or growth on the anus or inside their anal canal.   Anal warts usually do not cause discomfort or pain. Patients may experience  symptoms of itching, bleeding, discharge, or a sensation of pressure around the anus. The growths may go away on their own,  get larger or stay the same. They are frequently highly contagious and may infect the normal surrounding skin. The actual sites of infection are usually more than can be visually identified because they may  have already infected the normal surrounding skin and are still incubating.

Q: Who gets anal warts?
A:   Anal warts are predominantly caused by anal sex.  More women than men get anal warts because a greater number of  women have receptive anal sex than gay and bisexual men, who constitute a much smaller percentage of the population (CDC).

Q:  How does a person get anal warts?
A:  Anal intercourse is the most common cause of anal warts. People can also develop anal warts from being touched with fingers, whether during sexual foreplay or when cleaning or bathing.   The HPV virus has been identified to be present beneath the fingernails. Good hand hygiene is especially important for a person with a genital HPV infection because they may inadvertently spread the infection to a partner or to other sites on their own bodies.

Q:  How often is anal intercourse going on in the general population?
A:  According to the CDC, 20% – 40% of heterosexual couples have engaged in anal sex at least once.  10% of heterosexual couples practice anal intercourse on a regular basis. Women have receptive anal sex in greater numbers than men who have sex with men, because gay men represent a much smaller percentage of the population.   The incidence of anal warts continues to increase in both women and men.

Q:  What are the other ways  a woman can get an anal HPV infection?
A: The anatomic proximity of the vaginal opening to the anus in women facilities non-sexual ways of transmission. Leakage of infected vaginal secretions may infect the anus in this manner. The use of sex toys can also cause anal HPV infections.

Q:  What is the  prevalence of anal HPV DNA in heterosexual men?
A:  HPV DNA in heterosexual men has been detected in the anal canal 16% of the time and in the perianal area 21% of the time.  One-third of patients with anal HPV have the high risk strains.

Q:  What is incidence of anal HPV  in HIV negative women?
A:  There is a baseline prevalence of 27% anal HPV infection in HIV negative women.   70% of these women were noted on follow up to develop an anal HPV infection.

Q:  What is the duration of untreated anal HPV infection?
A:  Natural history studies show that the median duration for infection with a high  risk strain was 150 days (5 months). Anal infection cleared without treatment in 87% of women within one year.   This is a shorter time than the clearance rate for the cervix, where 90% of HPV infections take 2 years to clear.

Q:  What is the natural clearance rate of anal HPV?
A: Both oncogenic and non-oncogenic  anal HPV infections cleared on average in about 7.5 months.  HPV 16 , the strain most prominent in cervical cancer as well as in several other cancers, lasts just over 12 months.    Men with a higher number of female sex partners took longer to clear both high risk and low risk HPV stains. Men who are older are able to clear high risk HPV infections more quickly than their younger counterparts.

Q:  What is the latency period for HPV?
A: The average latency period of the virus ranges from  one to eight months. There are reported instances of HPV which had a  latency period of over one year.

Q:  Is the incidence of anal HPV infections going up or down?
A:  Infection of the anal region with HPV in both heterosexual men and non- HIV infected women is relatively common and is increasing.

Q:  Are most cases of anal genital warts dangerous?
A:  Most cases of anal warts are consist of low risk HPV strains (6/11), which can grow large, are very contagious but are benign and do not cause cancer.  If a person has a mixed infection that consists of both low and high risk strains, however, the high risk strains still have the potential to progress into a cancer.

Q:  Can anal genital warts be dangerous?
A:  A person who is infected with the high risk strains of HPV is at increased risk of the infection progressing into a cancer of the anus or rectum.  90% of anal cancers are caused by the high risk strains (16/18). HPV 16 is responsible for most cases of anal cancer. Treatment of anal cancer is over 80% successful if the growths are treated early.

Q:  What is the transmission rate of HPV in men and women?
A: HPV can be transmitted through any sexual activity that involves skin-to-skin or skin-to –mucosa contact including vaginal, anal, and oral sex.   Both symptomatic and asymptomatic individuals can transmit HPV to their sexual partner.

More than 50% of sexually active women in the U.S, are estimated to have been infected by one or more genital HPV types at some point in their lifetime.  Heterosexual HIV negative adult men have been shown to have an overall HPV prevalence of approximately 50%. Concordance of HPV between sexual partners is variable and ranges from 40% – 60%, which may be affected by length of sexual relationship, frequency of intercourse, condom use and number of lifetime sexual partners.  

Q:  How does the prevalence of anal and cervical HPV infection compare in women?
A: HIV negative women, including those with both low and high risk HPV strains,   have a greater incidence of anal HPV infection than cervical HPV infection. The prevalence of anal HPV infection in HIV positive women has also been demonstrated to be even higher than the prevalence of cervical HPV infection.

Q:  Should women with cervical disease get anal cancer screening?
A:  HPV in the anal canal of women is not uncommon.  Women have higher rates of anal HPV than cervical HPV.  Most of the anal infection is probably due to anal intercourse.   These woman should continue to be screen in order to ensure the early identification of disease.

Q:  How does the presence of multiple anal HPV Infection affect the chances of developing anal genital warts?
A:  The presence of high risk HPV significantly  increases the chance of developing anal warts.   A synergistic relationship between the high risk and low risk HPV infections may be present.   Woman with multiple types of anal HPV infections are more likely to contract additional infections as well as more likely to clear HPV infections faster than women infected with only one HPV type.  


Q:  How are anal warts treated?
A: There are several methods available to treat genital warts. The types of treatment approaches are divided into two categories: medical and surgical.

Certain medical treatments are prescribed and self-administered, meaning the patient themselves has control of their own treatment.

These treatments include: imiquimod (Aldara, Zyclara) sinecatechins (Veregen),  and podophyllotoxin (Condylox). 

Chemical treatments  that are applied by the physician in the office include trichloracetic acid (TCA) and podophyllin.   

Surgical treatments include removal by electrodessication, curettage, surgical excision, laser removal, cryotherapy (freezing) and IRC (infrared coagulation).

Ablative infrared coagulation (IRC) is a treatment option  to treat HPV growths in the anal and rectal canal in men and in women.

The choice of the treatment approach depends on the patient’s clinical presentation and the treatment preferences of the physician.  There are advantages and disadvantages to each treatment method.

A specific course of treatment will be recommended by the doctor depending upon the patient’s clinical presentation.  Genital warts can be successfully treated with an excellent healing result when a methodical and comprehensive approach is used.  HPV is a containable condition  and when treated correctly patients with HPV can realistically look forward to a life free of daily stresses from this condition.

Q:  Can the anal warts be treated in an office setting?  
A:  The treatment  of anal warts can in almost all cases be done in the office.  The patient can return to work the same day. Patients are usually in and out of the office in an hour or less.  The treatment is safe and the risks are minimal.

Q: Is treatment covered by insurance?
A: The treatment of anal warts if covered by insurance because it is a medically necessary service.


Q:  Why are the risk factors for getting anal cancers?
A:  The risk factors for anal cancer include receptive anal intercourse, sexual orientation, multiple partners, lack of condom use, being uncircumcised and having sex with men who are not circumcised, smoking, passive smoke exposure, race, ethnicity, and  educational level.

The number of anal cancers have doubled in the last decade and the number is continuing to rise.   MSM and HIV positive men and women have seen the most dramatic increase in anal cancers and have had the lowest survival rates.

Q:  What other conditions increase the risk of a women developing anal cancer?
A:  Specific risk factors for a women include having had receptive anal intercourse, multiple partners,  lack of condom use, sex with a man/men who are uncircumcised, smoking, passive smoke inhalation, and/or if the woman  has a history of having had cervical, vulvar or vaginal cancer.

Q:  What is the relationship between HPV and cancer?
A: HPV is responsible for 100% of cervical cancers  and 90% of anal cancers. The majority of anal cancers are caused by HPV 16 or 18.  HPV is a small un-enveloped , double –stranded DNA virus with over 100 different genotypes or strains identified.  At least 30 of these HPV strains are sexually transmitted and infect the top layers of the skin of the genial tract.

Q:  What is the prognosis for anal cancer?
A: Anal cancer like cervical cancer, is preventable and curable, especially if treated in the early stage of disease.  

Q:  What are symptoms of anal cancer?

A:   Pain or tenderness in the area around the anus, which can be constant or occur only with bowel movements or receptive sex
Bleeding with bowel movements

Lump or hard area on the outside of the anal area that appears to be increasing in size

Itching or discharge from the anus

Pain or a sense of fullness and a constant need to go to the  bathroom which may occur as tumors grow and begin to invade the sphincter muscle

Q:  How often does each of the HPV-related cancers occurs?
A:  The Anal Cancer Foundation published the numbers that appear below.

HPV-associated anal cancer 3,286 women and 1,916 men every year.
Cervical cancer 10,976 women/year
Oropharyngeal cancer 8,586 cases/year in men of HPV associated
1,881 cases /year in women of HPV associated
HPV-associated penile cancer 749 men/year
HPV-associated vaginal cancer 830 women HPV associated each year
HPV associated vulvar cancer 2,840 women /year


Q:  Are men who have sex with men  (MSM) at higher risk of getting anal warts?
A: Men who had sex with men (MSM)  have a higher risk of getting anal  warts. HIV positive gay men are at the highest risk of having persistent HPV throughout their lives.  Gay, bisexual and HIV positive men have a higher risk of getting anal cancer than women or heterosexual men diagnosed with anal HPV infections.

Q: What is the risk for gay men of getting an anal  HPV cancer?
A: Men who have sex with men (MSM) have the highest risk of developing anal cancers. The risk of anal cancer in MSM who are HIV negative and have a history of receptive anal intercourse is similar to the incidence of cervical cancer prior to the introduction of the Pap smear which allowed early detection and treatment of the condition.   

HIV positive men have a significantly increased risk of developing anal cancers compared to MSM who are HIV negative.  

Q: Why has there been such an increase in anal cancer?
A: HIV + individuals now have the benefit of more effective medications which have allowed HIV status to become a chronic disease because of increased survival rates.  Most MSM have anal HPV infections. Almost all HIV positive men have HPV infections. Anal cancers have an incubation period that can be 20 years or longer. HPV positive men used to die before anal cancers could develop before effective anti-HIV medications were developed.   HIV positive men now live longer and during the additional time in these men’s lives more anal cancers will develop. These individuals need to be diagnosed early so that proper treatment can be initiated.

Q:  Are the chances greater for an HIV positive man to get HPV?
A:  Infection by multiple high risk types of HPV has been associated with a greater likelihood of anal cancer precursors.  HIV-infected individuals, regardless of HIV risk factors, have a high prevalence of HPV infection and are at higher risk for anal cancer precursor, despite good virologic suppression of their HIV.    Anal HPV infection is almost universal among HIV infected men who have sex with men (MSM), with reported prevalence estimates between 87% – 98%.

Q:  What is the relationship between anal cancer and HIV?
A:  There are approximately 37 million people worldwide living with HIV at the end off 2014.  There are 1.2 million HIV infected individuals in the United States. Approximately 1% of women and 28% of men with anal caner also have an HIV infection.   Cancer is estimated to be responsible for over one-third of all deaths in HIV infected individuals The immnosuppresison associated with HIV infection reduces the ability to control  the oncogenic viral process, which explains the greater risk of infection-related cancer.

Q:  How does the incidence of anal cancer compare now to before antiretroviral therapy?
A:  Prior to the availability of high actively antiretroviral therapy (HAART), the estimated incidence of anal cancer amongst HIV infected MSM was 60 fold higher than men in the general population.   The incidence of anal cancer in HIV infected MSM is now estimated to be 80x higher than men in the general population. This increase in incidence of anal cancer has been shown to be associated with the HIV epidemic in men.    The incidence of HPV associated anal cancer has increased in the HAART era because more HIV positive men are living with HIV because they are not dying from opportunistic infections and other conditions.

Q:  How common are anal cancers in HIV+ MSM compared to women with cervical cancer?
A:   Anal cancer is a relatively uncommon cancer.  In the HIV positive MSM and HIV positive woman, however, it is a not uncommon cancer.    HIV positive MSM (men who have sex with men) have an incidence of anal cancer that is 10x the incidence  of cervical cancer in the general population of women who are not HIV positive.

Q:  Is concern for anal cancer more of a chronic issue for HIV positive MSM?  
A:   Now that we are in the antiretroviral  therapy (ART) era, the focus has shifted to get chronic complications  of HIV infection under control. It takes many years for an HPV infection to progress to cancer.  This progression was not a pressing issue in the past because people who were HIV positive did not live long enough for this to become a concern.  The introduction of highly efficacious anti-retroviral medications have enabled HIV positive individuals to live a relatively normal lifespan. The attentive evaluation and  treatment of patients for chronic complications of HIV is now more pressing.

Anal cancers are preventable.   The incidence of anal cancer went up in the HAART  (highly active anti-retroviral therapy) era rather than down because as more patients lived the high risk HPV growths had the opportunity to progress into anal cancer.

Q:  How does the incidence of HPV compare in HIV-negative compared to HIV-positive men in MSM?
A: HIV positive men are more likely to have high risk HPV strains than men who are not HIV positive.   93% of HIV- positive men have been found to have at least one HPV type compared to 64% of HIV-negative gay men.    74% of HIV positive men had at least one high risk HPV type, compared to 37% of HIV-negative men.

HIV infection increases the risk of HPV infection.  It has also been observed that HPV increases susceptibility to HIV infection.  

Successful treatment of HIV may reduce the risk of anal cancer for men living with HIV

Q:  What is the efficacy of the HPV vaccine in MSM who are older (greater than 42 yo)?
A:  The incidence and prevalence of genital warts in men decreases with age.  Nonetheless, older MSM still remain at risk for genital warts. Recurrence, defined  as reappearance of genital warts within 12 months after complete clearance, ranges from 4% – 50%, depending on the  treatment used and the immune competence of the patient. Older MSM are more likely to have been exposed to HPV in the past and over 50% are noted to be positive for oncogenic (high risk) HPV .   A large study of HIV-negative MSM found 26% prevalence of non-oncogenic (low risk) HPV types and 26% prevalence of oncogenic (high risk) HPV types within the anal canal across all age groups.

Q:  How often are multiple (high and low risk) strains found in MSM who are HIV negative?
A:  In MSM who are HIV negative, 45%  of those with anal HPV infections were infected with more than one HPV types, with both high and risk types present in lesions.

HPV Prevalence in the Anal Canal and Incidence of Anal Cancer in Men

Category Approximate prevalence rate
Prevalence in HIV-negative gay men 60%-75%
Prevalence in HIV-positive men 80% – 100%
Prevalence in men with multiple types of HPV, including high-risk types in HIV-negative gay men 25%
Prevalence in men with multiple types of HPV including high risk types in HIV Positive men 60%
Icidence of anal cancer in HIV-negative gay men 35/100,000 men
Incidence of anal cancer in HIV-positive Gay men 70/100,000 men
Incidence of anal cancer in general population 1-1.5/100,000 men

**Chart from: The HPV Vaccine Controversy by Shobha S. Krishnan, M.D. Praeger. 2008. Page 133

Anal cancer occurs 20x more frequently in gay men than heterosexual men. Anal cancer occurs over 60x more frequently in HIV gay men than in heterosexual men.

Q: Should anal pre-cancers be monitored or treated?
A: Many genital warts as well as cervical cancer precursors resolve on their own without treatment. There is an ongoing debate about whether anal –precancers should be monitored or treated.

There is a higher prevalence of high risk strains in the anus than in cervical lesions or genital warts. The lesions which are observed have a considerably greater chance of progressing into anal cancer. The most conservative approach is to treat the patient who has an anal precancer because patients often get lost to follow up and by that time the lesion may have advanced considerably or patients do not come for follow up until the lesions are considerably larger, more pronounced and a later stage of development.


Q:  Who will benefit from getting the HPV vaccine?
A:  The HPV vaccine is preventive but is not therapeutic.   The HPV vaccine offers protection against those strains of the virus  to which a person was not been previously exposed. The best hope for future generations is that young people get vaccinated at an early, age, before they have had many sexual contacts.    

Q:  Will the vaccine be effective against anal warts and anal cancers?
A:  The vaccine provides close to 100% protection against genital warts and pre-cancers.  The HPV vaccine contains seven high risk strains of HVP that protect against over 80% of the strains that cause HPV-related cancers.  The vaccine includes the high risk strains 16 and 18. People who get vaccinated will be protected from both high and low risk anal HPV infections.  90% of anal cancers are made up of HPV 16/18. HPV 16 is the strain involved in the majority of cases of anal cancer.

The vaccine is the most hopeful solution for the next generation.

Q:  When was the HPV vaccine approved for men?
A:  The FDA (Food and Drug Administration) approved the HPV vaccine to prevent initial infection against HPV 6, 11, 16, and 18 in women in 2006.  The FDA approved the vaccine for men in 2009. The vaccine has been demonstrated to be highly efficacious in preventing genital warts as well as the precursor stage to anal cancer.   Additional high risk strains have since been added to the vaccine in order to give an individual an even greater immunity and protection against strains that can cause cancer.

Q:  What are the benefits of the HPV vaccine in males?
A: The benefits of the HPV vaccine in males include the reduction of HPV-associated disease (genital warts and cancer) in boys and men and  the prevention of the transmission of the HPV virus to women.

Q:  What is the efficacy of the HPV vaccine to protect against anal warts in MSM 26 yo and younger?
A: HPV vaccine demonstrates 70% efficacy against external anogenital condyloma and 57% against intra-anal condyloma amongst MSM 26 yo and younger.  

Q:  What is the efficacy of the HPV vaccine in older MSM against anal genital warts?
A:  The HPV vaccine was demonstrated to decrease the risk of anal genital warts in older MSM. The lifetime risk for developing anal cancer was reduced by 60%. The HPV vaccine in men is currently FDA approved only for men 9-26 yo.. but in light of this data should be considered for off label use.

Q:  Does the HPV vaccine affect the chances of  HPV recurrences in women who previously had an HPV  infection?
A:  A 47%  decrease in recurrence of genital condyloma related to HPV types found in the vaccine was seen in   women who received the HPV vaccine. The study did not reach statistical significance.

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