Table 4 Analysis of pathologic features for the correlation with SMAD4 mutation of PDAC

Histologic grade

0.951

   Well-differentiated

5(2.45%)

5(2.23%)

   Moderately differentiated

120(58.82%)

135(60.27%)

   Ill-differentiated

79(38.73%)

84(37.5%)

Pathological fatty infiltration

0.016

   Absence

53(25.98%)

37(16.52%)

   Presence

151(74.02%)

187(83.48%)

Pathological peripheral nerve infiltration

0.039

   Absence

48(23.53%)

35(15.63%)

   Presence

156(76.47%)

189(84.38%)

Pathological lymphovascular invasion

0.249

   Absence

154(75.49%)

158(70.54%)

   Presence

50(24.51%)

66(29.46%)

Ki-67 expression status

0.490

   ≥ 50%

120(58.82%)

125(55.8%)

   < 50%

83(40.69%)

99(44.2%)