PMBCL: role of RT

[Kroll2013]

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Dear Colleagues, I would like your opinion concerning my patient
39 years old female with no comorbidities, clinically presented for cough
- was diagnosed with a Stage II bulky PMBCL
- Pet CT: large superior mediastinal mass , multiple nodes in the chest 6*10cm, + N (suprahilar, right lower paratracheal )

- She received 3 cycles of R-CHOP
- Interim Pet: Deauville 1
- Followed by 3 cycles R-CHOP
- last Pet CT Deauville 1 Complete remission and no residual fibrosis on the CT where the bulky lesion was.

would you still give consolidative RT ?

 

[Gfunk6]

No, omit.

IELSG-37 trial (JCO 2024): Randomized PET-negative PMBCL patients after immunochemotherapy to RT vs observation.

No diff in OS in 5 years

 

[TheWallnerus]

Never forget Eli Glatstein telling us residents in about 1999 “We are just one drug away from being out of the lymphoma game.”

 

[RickyScott]

Never forget Eli Glatstein telling us residents in about 1999 “We are just one drug away from being out of the lymphoma game.”

also sums up GI and now bladder.

 

[TheWallnerus]

also sums up GI and now bladder.

He further elaborated as Eli was oft wont to do that the phrase could be applied in various other clinical scenarios!

If you guys saw this recent podcast by Eli Lilly CEO on AI and drug discovery we are about to immanentize the oncologic eschaton

 

[RickyScott]

He further elaborated as Eli was oft wont to do that the phrase could be applied in various other clinical scenarios!

If you guys saw this recent podcast by Eli Lilly CEO on AI and drug discovery we are about to immanentize the oncologic eschaton

Bladder came out of the blue. Solid malignancy w/60% pCR in poor ps. My guess is that it will also happen with lung in next 5-10yrs

 

[TheWallnerus]

Bladder came out of the blue. Solid malignancy w/60% pCR in poor ps. My guess is that it will also happen with lung in next 5-10yrs

 

[HolySmokes]

Out of curiosity, why R-CHOP and not DA-R-EPOCH? I still recommend omitting, but would feel better about it with the escalated systemic tx.

 

[A_DeMichele]

Bladder came out of the blue. Solid malignancy w/60% pCR in poor ps. My guess is that it will also happen with lung in next 5-10yrs

which study is that? will that replace RT in bladder preservation?

 

[Palex80]

which study is that? will that replace RT in bladder preservation?

KEYNOTE-905​

Here's a recap

https://www.urotoday.com/conference-highlights/esmo-2025/esmo-2025-bladder-cancer/164063-esmo-2025-a-new-era-in-the-treatment-of-muscle-invasive-bladder-cancer-discussant-of-lba2-perioperative-periop-enfortumab-vedotin-plus-pembrolizumab-in-participants-with-muscle-invasive-bladder-cancer-who-are-cisplatin-ineligible-keynote-905-study.html

 

[RickyScott]

KEYNOTE-905​

Here's a recap

https://www.urotoday.com/conference-highlights/esmo-2025/esmo-2025-bladder-cancer/164063-esmo-2025-a-new-era-in-the-treatment-of-muscle-invasive-bladder-cancer-discussant-of-lba2-perioperative-periop-enfortumab-vedotin-plus-pembrolizumab-in-participants-with-muscle-invasive-bladder-cancer-who-are-cisplatin-ineligible-keynote-905-study.html

Not unreasonable to think that adding cis could increase path cr by 10%. Real paradigm shift here for oncology. Radonc becoming the long snapper on the cancer football team.

 

[A_DeMichele]

these data raise important questions about whether such high response rates could open the door for future bladder-preservation strategies. too early to say it will replace RT there

 

[Mandelin Rain]

these data raise important questions about whether such high response rates could open the door for future bladder-preservation strategies. too early to say it will replace RT there

Would be nice if the RTOG portion of NRG would jump on this. Pretty simple design, if post systemic cysto is negative, treat with chemorads for preservation. If positive, proceed with cystectomy.

 

[medgator]

Would be nice if the RTOG portion of NRG would jump on this. Pretty simple design, if post systemic cysto is negative, treat with chemorads for preservation. If positive, proceed with cystectomy.

That would make too much sense

 

[RickyScott]

Would be nice if the RTOG portion of NRG would jump on this. Pretty simple design, if post systemic cysto is negative, treat with chemorads for preservation. If positive, proceed with cystectomy.

If negative, and ct dna negative don’t treat is where this is going. CTdna in bladder was also shown to direct adjuvant therapy.

 

[Palex80]

Would be nice if the RTOG portion of NRG would jump on this. Pretty simple design, if post systemic cysto is negative, treat with chemorads for preservation. If positive, proceed with cystectomy.

Why not simply not treat at all if cysto is negative?

If we assume that IO resulted in this meaningful response, next to the ADC, consolidation RT might even kill all those helpful lymphocytes in the bladder wall and lymphatics that are supposed to fight the micro-tumor-deposits.