Recurrences

[doctalaughs]

Anyone else have trouble believing the literature about recurrence rates of NMSC? It seems that recurrence after excision of even low risk BCC/SCC (ie small and no other high risk factors) should be 5-10% in the few large studies (most done by mohs people).

I personally have seen less than 10 recurrences after thousands of excisions over close to decade. Definitely more after ed&c, which would be expected, but even in this case Im guessing 2-3% max (whereas literature is like 15-25%). Of course, these are low risk ones (high risk goes to mohs) but still doesn't seem to match the literature. Any other experiences here compared with expected rates?

---

Members don't see this ad.

 

[MOHS_01]

I cannot comment on the percentages as I don't know the denominator in these equations, but 40 something percent of my cases 2012-2014 were recurrent tumors and the vast majority of those were excisions with free margins. Of these, most were iBCC's within 3 years of excision. Even more telling, IMO, is the number of positive margins I see on standard excisions when the lab goes ahead and processes the specimens as they would a Mohs layer - that's embarrassingly high, not only for myself but my former colleagues who would have us prepare slides for them.

My gut feeling is that recurrence rates vary with relation to size, location, and histology -- exactly what the literature suggests. If you are primarily treating low risk nBCC's and small well diff SCC's, I suspect the recurrence rate is in fact lower than reported. I imagine that the recurrence rate for aggressive histology tumors is significantly higher than reported. I would lay large sums of money that any BCC on the distal third of the nose (or perialar cheek), approaching the vermillion lip, or on the ear (excluding small nBCC strictly on the rim) would have a recurrence rate no one would want their name attached to.

Excisions are the go to for appropriately selected tumors; I will often excise something referred to me for Mohs. Unfortunately I also see many excisions that I believe were ill advised... I don't think people have an appropriate respect for the frequency of mixed histology in BCC's nor the frequency of perineural involvement.

...of course I have a 95% outside referral practice, too, so my prism is heavily skewed....and have somehow developed the reputation of being the clean up man.

 

[MOHS_01]

We hope to answer this with the DataDerm registry, btw. Many people never see their own recurrences...

 

[doctalaughs]

We hope to answer this with the DataDerm registry, btw. Many people never see their own recurrences...

This makes sense. 40% recurrences in your practice is extremely high though! Are most of these coming from general derm, primary care or other surgical specialists? For example, our referral pattern my partners and i would say send 97%+ primary tumors and less than 3% recurrences to mohs. And we are pretty good at treating most tumors that we can (I'd guess 1 in 20 goes to mohs).

I would be interested in a study of recurrence rates of appropriately selected low-risk tumors- I'm guessing it would be very low. Also i don't think a lot of people use dermoscopy to mark tumor edges before excising.

 

[MOHS_01]

This makes sense. 40% recurrences in your practice is extremely high though! Are most of these coming from general derm, primary care or other surgical specialists? For example, our referral pattern my partners and i would say send 97%+ primary tumors and less than 3% recurrences to mohs. And we are pretty good at treating most tumors that we can (I'd guess 1 in 20 goes to mohs).

I would be interested in a study of recurrence rates of appropriately selected low-risk tumors- I'm guessing it would be very low. Also i don't think a lot of people use dermoscopy to mark tumor edges before excising.

Yeah... I feel that way too -- it's like I get stuck with the **** that the other guys don't want to deal with. We also have some fairly aggressive dermatologists in the area who will excise something two, three, or even four times before referring -- it's an interesting culture.

Maybe I should come visit your neck of the woods -- ha.

I'm sure that most do not use dermoscopy -- I don't. :embarrassed: Maybe I'll start now.

 

[doctalaughs]

Excising more than once (unless you missed a focal area initially) sounds crazy.

Unfortunately I think derm groups mostly fall in two categories - those that have mohs in-house and are sending way too much, and those that don't and are sending too little/late.

The place I used to work basically did this: everything (I mean everything) neck or above, shins, dorsal hands went mohs. Everything not superficial or nodular (even if it was 2mm on the back) went to mohs (in house of course).

On the other hand excising things 2, 3, 4 times is crazy. Excising large, infiltrative or poorly diff things in high risk sites is crazy.

Sounds like its easier (case wise) if you are a mohs surgeon in a big derm group. I think these groups are the ones creating the fuel about over-utilization.

 

[Slack3r]

Excising more than once (unless you missed a focal area initially) sounds crazy.

Unfortunately I think derm groups mostly fall in two categories - those that have mohs in-house and are sending way too much, and those that don't and are sending too little/late.

The place I used to work basically did this: everything (I mean everything) neck or above, shins, dorsal hands went mohs. Everything not superficial or nodular (even if it was 2mm on the back) went to mohs (in house of course).

On the other hand excising things 2, 3, 4 times is crazy. Excising large, infiltrative or poorly diff things in high risk sites is crazy.

Sounds like its easier (case wise) if you are a mohs surgeon in a big derm group. I think these groups are the ones creating the fuel about over-utilization.

Gotta get those RVUs.

 

[MOHS_01]

Excising more than once (unless you missed a focal area initially) sounds crazy.

Unfortunately I think derm groups mostly fall in two categories - those that have mohs in-house and are sending way too much, and those that don't and are sending too little/late.

The place I used to work basically did this: everything (I mean everything) neck or above, shins, dorsal hands went mohs. Everything not superficial or nodular (even if it was 2mm on the back) went to mohs (in house of course).

On the other hand excising things 2, 3, 4 times is crazy. Excising large, infiltrative or poorly diff things in high risk sites is crazy.

Sounds like its easier (case wise) if you are a mohs surgeon in a big derm group. I think these groups are the ones creating the fuel about over-utilization.

Matches my experience perfectly.

 

[MOHS_01]

Oh - missed the question contained therein the first time. Fewer than 1% of my referrals for Mohs are from non-dermatologists.

 

[asmallchild]

This makes sense. 40% recurrences in your practice is extremely high though! Are most of these coming from general derm, primary care or other surgical specialists? For example, our referral pattern my partners and i would say send 97%+ primary tumors and less than 3% recurrences to mohs. And we are pretty good at treating most tumors that we can (I'd guess 1 in 20 goes to mohs).

I would be interested in a study of recurrence rates of appropriately selected low-risk tumors- I'm guessing it would be very low. Also i don't think a lot of people use dermoscopy to mark tumor edges before excising.

Interesting, do you find it helps significantly?

I'll use the dermatoscope more as an academic exercise when marking out margins for mohs layers but never trusted myself to use it to determine excision margins

Agreed regarding the recurrence rate: my limited experience seems to show a much lower rate but then again, I'm in one of those practices that tries to filter everything to the mohs surgeon

 

[doctalaughs]

Interesting, do you find it helps significantly?

I'll use the dermatoscope more as an academic exercise when marking out margins for mohs layers but never trusted myself to use it to determine excision margins

Agreed regarding the recurrence rate: my limited experience seems to show a much lower rate but then again, I'm in one of those practices that tries to filter everything to the mohs surgeon

I find it helps a lot for BCC in particular. Most SCCs are easy to see by the naked eye but its very often with BCC that my marked margins by dermoscopy differ significantly from what I would do by eye alone. I also think unless its large or infiltrative its very rare to not see some surface changes above the very furthest extent of the tumor.

 

[MOHS_01]

I had a bad one today; nice older gentleman, snowbird... has been dealing with series of SCC's in a straight line up forehead. First bx was in Nov '14, then surgery every two to three weeks from Nov-March Comes in today with two biopsies, SCC, along the linear line of second intention scar. Yep, perineural and through the muscle.... today he had two other crusted erosions along that same line -- all told around 11cm in length, 2.5 in width... with another crusted erosion probably 3cm removed, same line. Ugh.

 

[doctalaughs]

I had a bad one today; nice older gentleman, snowbird... has been dealing with series of SCC's in a straight line up forehead. First bx was in Nov '14, then surgery every two to three weeks from Nov-March Comes in today with two biopsies, SCC, along the linear line of second intention scar. Yep, perineural and through the muscle.... today he had two other crusted erosions along that same line -- all told around 11cm in length, 2.5 in width... with another crusted erosion probably 3cm removed, same line. Ugh.

Were all those surgeries from nov - march for the same tumor recurring or were they all separate (ie terrible field damage or prior radiation)? Was the SCC that recurred on the secondary intent scar originally have any high risk features? Curious.

 

[MOHS_01]

Were all those surgeries from nov - march for the same tumor recurring or were they all separate (ie terrible field damage or prior radiation)? Was the SCC that recurred on the secondary intent scar originally have any high risk features? Curious.

No history of radiation -- they represented the development of new nodules / erosions along a line but not directly adjacent to the previous surgeries. They considered them reactive keratoacanthomas. It was perineural, something that was never identified in the biopsies or subsequent excisions.

 

[doctalaughs]

No history of radiation -- they represented the development of new nodules / erosions along a line but not directly adjacent to the previous surgeries. They considered them reactive keratoacanthomas. It was perineural, something that was never identified in the biopsies or subsequent excisions.

Scary. Ive seen lots of reactive or eruptive ka-like lesions on the legs and even a few on the trunk but face should raise a lot of brows.