Patterns of pathologic lymph nodes in anal cancer: a PET-CT-based analysis with implications for radiotherapy treatment volumes

Table 4 Common iliac and/or para-aortic (CI/PA) PET-positive lymph nodes in different subgroups

	CI/PA PET-positive lymph nodes^a
	No, n (%)	Yes, n (%)	P-value
T stage			0.75^b
T1–3	61 (86%)	10 (14%)
T4	29 (91%)	3 (9%)
Lymph node regions^c with PET-positive lymph nodes			0.04
< 3 regions	67 (92%)	6 (8%)
≥ 3 regions	23 (77%)	7 (23%)
Site of PET-positive lymph nodes
Inguinal	67 (89%)	8 (11%)	0.33
Internal iliac	21 (75%)	7 (25%)	0.02
External iliac	24 (73%)	9 (27%)	0.004^b
Perirectal	29 (83%)	6 (17%)	0.32

^a At the time of anal cancer diagnosis; i.e., not recurrence
^b Fisher’s exact test; chi square for all other P-values
^c 7 regions: left inguinal; right inguinal; left internal iliac; right internal iliac; left external iliac; right external iliac; perirectal

ISSN: 1471-2407