ESTRO 2025 - Abstract Book

S1233

Clinical – Lower GI

ESTRO 2025

Fig. 2 Overall Survival Analysis for Rectal NEC before Matching

Table 1 Subgroup Survival Analyses of Rectal NECs by Clinical stage after Matching

Median OS (months)

Stage

No.

HR (95CI)

P

non-RT

RT

I

68

88.0

171.0

1.00(0.51-1.96)

0.6679

II

70

12.0

24.0

0.36(0.21-0.63)

<0.001

III

284

18.0

22.0

0.75(0.57-0.98)

0.0315

IV

160

8.0

7.0

0.69(0.50-0.95)

0.0118

Conclusion: Radiotherapy was an independent favorable prognostic factor for rectal NECs. The addition of radiotherapy to surgery plus chemotherapy improved the clinical outcome. Our study may help guide better treatment decisions and prolong the survival for these patients.

Keywords: Rectal carcinoma, NEC, Radiotherapy, outcome

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