Comparison of the Subgross Distribution of the Lesions in Invasive Ductal and Lobular Carcinomas of the Breast: A Large-Format Histology Study

Table 3

Relative risk of having lymph node metastasis in ductal and lobular breast carcinomas by lesion distribution, Dalarna, Jan 2008–Jul 2012.

		Unifocal	Multifocal	Diffuse	Relative risk; multifocal versus unifocal	Relative risk; diffuse versus unifocal
	Ductal	27.5% (102/371)	53.8% (112/208)	86.7% (6/7)	RR = 1.9585; 𝑃<0.0001; (1.5912–2.4106)	RR = 3.1176; 𝑃<0.0001; (2.2088–4.4005)
Invasive component	Lobular	18.9% (7/37)	34.4% (21/61)	48.6% (17/35)	RR = 1.8197; 𝑃=0.1185; (0.8582–3.8585)	RR = 2.5673; 𝑃=0.0136; (1.2138–5.4303)
	Total	26.7% (109/408)	49.4% (133/269)	54.8% (23/42)	RR = 1.8507; 𝑃<0.0001; (1.5136–2.2629)	RR = 2.0498; 𝑃<0.0001; (1.4908–2.8184)
	Ductal	33.1% (83/251)	43.5% (64/147)	43.3% (68/157)	RR = 1.3534; 𝑃=0.0192; (1.0506–1.7435)	RR = 1.3098; 𝑃=0.0351; (1.109–1.6835)
In situ* component	Lobular	16.0% (4/25)	40.2% (37/92)	33.3% (3/9)	RR = 2.5153; 𝑃=0.0526; (0.0989–6.3841)	RR = 2.0833; 𝑃=0.2642; (0.5743–7.5575)
	Total	31.5% (87/276)	42.3% (101/239)	42.8% (71/166)	RR = 1.3406; 𝑃=0.0119; (1.0668–1.6848)	RR = 1.3569; 𝑃=0.0156; (1.0595–1.7377)
	Ductal	29.9% (73/244)	42.2% (78/185)	43.9% (69/157)	RR = 1.4093; 𝑃=0.0085; (1.0913–1.8198)	RR = 1.4690; 𝑃=0.0039; (1.1316–1.9069)
Combined in situ + invasive components	Lobular	20.0% (4/20)	31.9% (23/72)	43.9% (18/41)	RR = 1.5972; 𝑃=0.3284; (0.6245–4.0854)	RR = 2.1951; 𝑃=0.1020; (0.8555–5.6328)
	Total	29.2% (77/264)	39.3% (101/257)	43.9% (87/198)	RR = 1.3474; 𝑃=0.0156; (1.0581–1.7158)	RR = 1.5065; 𝑃=0.0011; (1.1790–1.9250)

*5.3% (31/586) of the ductal and 5.2% (7/133) of the lobular cases had no demonstrable in situ component.