Sunday, May 29, 2011

Prostate Cancer Invading The Seminal Vesicle: Prognosis and Treatment

I have recently heard from many new friends here and on some patient forums with concerns about seminal vesicle involvement by prostate cancer.  Often times, when giving a patient his pathology result after a prostatectomy, the urologist will mention the seminal vesicle but not explain its significance or, more importantly, the significance of involvement of the seminal vesicle by prostate cancer.  In this post, I want to shed some light on what the seminal vesicles are, why it is important to know if prostate cancer invades them, and what can be done once seminal vesicle involvement is determined after a prostatectomy.

 The Seminal Vesicle Exposed

A good place to start this discussion is to provide a little background about the seminal vesicle.  As its name implies, the seminal vesicle is basically a container for semen.  Two such seminal vesicles are located behind the prostate.  On diagrams, they look like bunny ears emerging behind the prostate and the bladder.  The seminal vesicles, along with the prostate, produce most (about 90%) of the semen released during ejaculation.  They are attached to the prostate and actually have ducts which empty into the center of the prostate.  This is the part of the prostate through which the urethra travels into the bladder (the “donut hole”).  These ducts connect to those of the tubes carrying sperm from the testes (the vasa differentia).  When ejaculation occurs, the sperm from the vasa differentia mix with the semen produced by the seminal vesicles and the prostate in the part of the urethra travelling through the prostate. The whole mixture is then propelled out through the urethra and penis by means of a forceful contraction of the muscles of the pelvis (this contraction is what provides the feeling of an orgasm).  As is probably clear from this description, the seminal vesicles are intimately associated with the prostate. As a result, prostate cancer that has escaped the prostate can proceed to directly invade the seminal vesicles.

Prostate Cancer and the Seminal Vesicle

Prostate cancer invades the seminal vesicles in about 3-7% of men with the disease.  Historically, invasion of the seminal vesicle by prostate cancer has been considered a sign of a very poor prognosis for men with prostate cancer.  In the past, studies reported that 50% of men with seminal vesicle invasion actually had metastatic disease at the time of surgery and, in fact, invasion of the seminal vesicle, itself, has been considered metastatic disease by many urologists.  This idea was supported by the fact that the majority of patients with seminal vesicle invasion demonstrated a rather quick biochemical recurrence after prostatectomy. This rapid recurrence of PSA after prostatectomy often led to subsequent documented metastatic disease.  As a result, the survival rate for men with seminal vesicle invasion was historically reported to be as low as only 32% at 7 years. 

With the era of PSA testing, outcomes for men with prostate cancer invading the seminal vesicles have been somewhat more encouraging.  The chance of a PSA recurrence within 10 years of prostatectomy remains very high (around 80%) for men found to have seminal vesicle invasion.  The rate of metastatic disease, as well, remains high at 44% for these men at 10 years after surgery.  However, these high rates of recurrence and metastasis do not appear to the lead to the dismal survival rates I previously mentioned.  In fact, recent studies demonstrated that at 10 years after surgery, men with invasion of the seminal vesicles demonstrated an overall survival rate of 61%.  In addition, a cancer specific survival rate of 84% has been described for these men.  That statistic is pretty astounding if you think about it: despite extremely high recurrence and metastasis rates, only about 16% of men with seminal vesicle invasion died of prostate cancer at 10 years after surgery!  This discrepancy is most likely a strong testament to the efficacy of hormonal therapy in managing metastatic disease.

Managing Seminal Vesicle Invasion

Because of the high rates of metastatic disease and poor prognosis associated with seminal vesicle invasion, patients with this finding have often been treated as if they had metastatic disease.  As a result, doctors have waited for early signs of a PSA recurrence after which they initiated hormonal therapy to manage impending metastatic disease.  Even with such a pessimistic, conservative approach, the impressive 10 year cancer specific survival of 84% mentioned above was attained for men with seminal vesicle invasion at 10 years after surgery.

Recently, however, a new, viable treatment option has become available for men with seminal vesicle invasion thanks to a randomized trial published in 2008.  The SWOG 8794 trial included 139 men that were found to have seminal vesicle invasion with or without positive margins or extracapsular extension (I cover both of these topics in prior posts).  These men were randomized into 1 of 2 treatment arms:

1)    Adjuvant Radiation Therapy
2)    Observation

Of note, men in the observation arm of the study could be treated at the digression of their physicians once a recurrence was documented.  This treatment could include either delayed radiation or hormonal therapy. 

The study demonstrated that men undergoing adjuvant radiation therapy enjoyed a significantly higher freedom from recurrent disease of 36% versus 12% for those in the observation arm.  In addition, men undergoing the radiation therapy appeared to be half as likely to need long term hormonal therapy as those in the observation arm.  The study also found that, after 10 years of follow up, men undergoing adjuvant radiation therapy enjoyed a higher rate of freedom from metastasis (66% versus 47%) and a higher overall survival rate (71% versus 51%) as compared to those men undergoing observation and possible delayed treatment.  The differences in freedom from metastasis and in overall survival, although impressive, were not statistically significant.  This lack of statistical significance is most likely due to the 10 year follow up of the study, the small overall number of patients, and the fact that men in the observation arm did receive hormonal therapy or salvage radiation therapy. Nonetheless, the results of the study are clinically significant and have really changed the approach to managing prostate cancer in men with seminal vesicle involvement. Rather than waiting for recurrent cancer and palliatively treating metastatic disease, many doctors are now aggressively treating men with seminal vesicle disease with adjuvant radiation therapy.  While the side effects of radiation need to be kept in mind, the potential benefit of this adjuvant radiation therapy appears to be substantial.  Another fact important to point out is that the dose of radiation administered to patients in this study was fairly modest as compared to that received by contemporary patients.  As such, one would imagine that the results of the study would be even more impressive if current radiation doses were used.

Take Home Message

Invasion of the seminal vesicle is usually a sign of an aggressive cancer, very different from the “run of the mill” Gleason 6, localized disease usually thought of when referring to prostate cancer.  Seminal vesicle involvement is a poor prognostic indicator associated with high rates of recurrence and metastatic spread.  In the PSA era, however, seminal vesicle involvement no longer appears to be the death sentence it was historically thought to be.  Aggressive management with adjuvant radiation can delay prostate cancer recurrence and spread.  In addition, the prudent use of hormonal therapy to manage metastatic disease can lead to many more years of life.  Overall, while certainly a serious condition to deal with, seminal vesicle invasion can still be successfully treated when encountered in men with prostate cancer.

Check Out My New Book:

Prostate Doc's Guide To Life After Prostatectomy

Share your Prostate Stats and learn from those of others!

This blog is not a medical practice and cannot provide specific medical advice. This information should never be used to replace or discount the medical advice you receive from your physician 


  1. I was advised today that I had a T3C prostrate cancer that has invaded my seminal vesicles. My medical team have advised a 6 month course of hormone treatment to be followed by radiotherapy. I was anticipating radical surgery as the first step and my head tells me that removal is a logical thing to be doing first.
    I have read your excellent posts tonight and am now unsure what to do.... second opinion to check out if radical surgery is the right move? or just get on with my medical teams advice.

    59 years old and confused..... can you shed any light on this dilemma for me?

  2. Balnastraid: While I cannot give individual medical advice through this blog, I do have some thoughts. Young, healthy men with T3C prostate cancer present a dilemma for urologists. As I mentioned in my post, the current thought is that men with T3C disease most likely has some prostate cancer that has spread locally or distantly. As a result, many urologists feel that surgery will not be successful as it probably wont get rid of all of the cancer. That, in combination with the good data from Europe about the results of a combination of radiation and 36 months of hormonal therapy ( see my post on timing of hormonal therapy), leads many urologists/oncologists to recommend some variant of the treatment course you were offered. That being said, some urologists try to be more agressive with younger men, opting to do at least a "debulking" surgery which gets rid of most of the cancer and then proceeding with radiation and possibly hormones. The decision depends on the clinical exam, PSA, presence or suspicion of lymph node or bone metastases, physician mentality, lifestyle/quality of life choices, and patient desire. As for a second opinion, that is something I recommend to all men diagnosed with prostate cancer. Fortunately, prostate cancer is not a heart attack and gives you the luxury of a little time to make up your mind. A second opinion may give you more confidence with your current treatment plan or make you realize that you need to choose a different path. In addition, comfort with your treatment team is almost as important as the treatment plan itself. Hope that helps.

  3. That is extremely helpful and is sound advice. "De-bulking" (great term) surgery seems an obvious step to a younger person who feels he wants an aggressive approach to trying to beat the cancer.

    Does a patient who has previous undergone some initial hormone therapy still have the option of "de-bulking" surgery. It's not clear to me from all that I have read on the subject.

    Thanks for trying to help us out here trying to pick our way through the options available. It's much appreciated.

  4. Balnastraid: Prostatectomy can still be carried out after hormonal therapy is initiated. As I mentioned, prostatectomy in patients with seminal vesicle disease can have higher complication rates. A thorough discussion with a urologist about all of the risks is extremely important. Glad to help!

  5. Balnastraid, I'm a high-risk G-9 positive vesicle patient..I'm being treated with all three, surgery, RT, HT..The surgery was worth a try and if it fails (in my case it did) at least 98% of the cancer was removed, giving the RT/HT FAR less work to do and improving the chances for success..I'm one year out from diagnosis, still on HT, PSA undetectable...

  6. Thanks for the encouragement Fairwind ..... i think I also will be going down the same treatment path ...seems to make sense.

  7. Seminal Vesicle Invasion for me. Radical Prostatectomy for me in Jan 2010. RT started in March 2010 for 39 doses. Have been on HT since - 90 day release - Zoladex.
    So far PSA is undetectable. Feeling great.

  8. Age 53. Just had robotic prostatectomy on Dec. 10. PSA prior to surgery was 12.3. Biopsy positive on 9 of 12 cores. Gleason - 7 (3+4). Post-op Gleason lowered to 6. Margins were negative and lymph nodes (also removed) were negative. However there was SVI. Haven't had a follow-up yet for post-op PSA. Gleason of 6, neg margins and no lymph node involvement seems to contradict SVI but that's what I've been told. Doc suggested I consider radidiation. Seems like the prudent approach. Worried right now.

  9. Sonny Jan 17,2013 at 9:07 am
    jgmcbride &Chaz: Age 71, had robatic prostatectomy on Dec 26. SVI on the left side. Will have post-op PSA and see the Doc on Feb 12. Chaz, I am fighting incontenece and worring like you. Please post what your doc finally plan for you.

    jgmcbride: What is your post-op PSA? RT used in your case was low dose or regular dose? What kinds of side effect from RT and HT? Thanks.

  10. sanit, I have my first post-op PSA on Feb. 15. Had a urologist friend of mine recommend against RT unless the PSA starts to rise...why do it if it's not necessary...right? We'll see. Have an appt with a radiation oncologist at the end of Jan.

  11. Chaz: I also will have my first post-op PSA on Feb 12. I am worry about the score and what the urologist is going to say. As your urologist friend reccomentation, it seems to me that is against The Prostate Doc above article which says: "Rather than waiting for recurrent cancer and palliatively treating metastatic disease, many doctors are now aggressively treating men with seminal vesicle disease with adjuvant radiation therapy." and, "Aggressive management with adjuvant radiation can delay prostate cancer recurrence and spread. In addition, the prudent use of hormonal therapy to manage metastatic disease can lead to many more years of life."
    Please share what you learn from the radiation oncologist. Thanks.

  12. sanit, the RT is a tough call. While I appreciate the philosophy of being aggressive there's also the possibility of the surgery being curative and the RT being over-treatment. There are docs on both sides of the issue and there aren't a ton of studies with significant follow-up timelines that makes it an easy decision one way or the other. My mother died recently (at 90) of MDS which can be triggered by radiation exposure and/or chemo. So...I've got that to consider. Also, my post-op path report indicated a Gleason score of 6 so a little less aggressive than some. What was your post-op Gleason? With my negative margins and LN there some accounts a good chance that my surgery was curative.
    The Sloan-Kettering nomogram would indicate that I have a 92% chance of remaining re-current free at 10 years based on my pathology. dilemma with RT. Will have to see what the oncologist says and what my PSA result is.

    1. Chaz: I am in worse shape than you. I am 71. My post-op was a Gleason 7, T3b, positive left seminal vesicle,focally positive margin adenocarcinoma of the prostate. I don't know much about the Sloan-Kettering nomogram. Would you please check it for me, if you don't mind?

  13. sanit, here is a link to the nomogram.

    I would encourage you to join the Prostate Cancer Infolink.

    Join the social network that is part of the website. Ask lots of questions. It has helped me to understand a few things about my because I had positive seminal vesicle doesn't mean the surgery wasn't curative. Longevity runs in my family so I'm possibly looking at 40-45 years of having to try to deal with this disease if it wasn't curative. I figure there will be new methods for curing it or at least keeping it in regression as the years roll by. There are lots of treatment options available...studies you can participate in...keep your chin's not a death can be managed.

    1. Chaz:Thanks.I will look into both links.

    2. sanit, the radiation oncologist agreed with my assessment that my post-op path is in kind of gray area and since I had neg margins and no ECE that RT was probably not necessary at this time. I will be closely monitoring my PSA and if it rises then I'll pursue RT. I see you joined the Infolink social network.

    3. Chaz: Thanks for sharing. I will wait and see my PSA on Feb 12.

  14. I had a RALP via daVinci. My seminal ducts and some lymphs were taken out as precaution, but were clear. Can I get some kind of surgery to replace the ducts so I can ejaculate normally again?

  15. chris - i am waiting my psa post op test and then talking with my radiologist. as my pre op gleason was 7 , my psa 3.5 ( low), while all other evidence indicated aggressive cancer, then post op it was discovered I had SVI in one outer membrane but no current other spread to outer margins / bones or lymph glands. their current recommendation is that I have adjunct radiotherapy for 6 weeks plus possible hormone therapy for 1 year. it seems that with this treatment I have better possibility of non re-occurrence and 10 year life expectancy than wait and see. i am at a good advanced treatment centre ( UCH London) and hope that new more focused and higher doses of radiation will work better. is this true - are there more recent studies showing whether there is significant improved life chances with this approach? on the other hand it seems there is at least a 4% chance that the result can be horrible side effects with complete loss of bladder and bowel control and other serious impacts. my wife urges me to consider quality and well as length of life. what do others think - has the chances of radical negative side effects reduced with more recent treatments?
    finally are there any trials / tests going on that indicate better outcome treatments - like proton therapy?