Dynamic breast MRI became an important tool for diagnosing and grading breast cancer. With the help of contrast medium not only morphology of the cancer but also its functional characteristics can be showed [5]. The potential relationship between MRI characteristics and prognostic factors is discussed by some researchers; however, there are controversial results because of different MRI techniques and evaluating criteria [6].
According to current data a mild background breast enhancement is related with ER presence, a good prognostic marker. Also, another current study stated that mild background parenchymal enhancement predicts good prognosis, and it is related with a negative HER2 expression. This condition might be the consequence of rarity of angiogenic-inflammatory factors in less aggressive ER-positive lesions [7, 8]. In line with the literature, we defined a positive correlation with mild parenchymal enhancement and ER presence/good prognosis.
There are controversial studies about lesions’ shape and prognostic factors especially histological grade. Shapes of the lesions on MRI were stated to be related with histopathological grade and Ki-67 values in one study; however, this relationship cannot be confirmed by other studies [6, 9, 10]. According to our results, irregular lesion shape is weakly related with a high Ki-67 index, but there is no relationship between lesion shape and histological grade.
T2* values were considered to be an imaging biomarker related with prognosis in breast, prostate, and head/neck cancer [11]. Partially similar with the literature, we found that intermediate signal intensity on T2WI was correlated with non-augmented c-erb B2 status/good prognosis.
Peripherally contrast enhancement is described as a poor prognostic factor in the literature, it is found to be related with ER absence, high histological grade, and high Ki-67 index [6, 12]. Also, a high contrast enhancement ratio was found to be related with a higher Ki-67 index and a worse prognosis [13]. However, there is an another study saying contrast enhancement pattern is not related with prognostic factors [14]. In our study, we cannot detect any relationship between contrast enhancement pattern and prognostic factors.
We found a relationship between a type III kinetic curve and a high Ki-67 index, consistent with the literature [6, 12, 14, 15]. We cannot detect any relationship between kinetic curve type and histopathological grade, ER presence/absence, similar to the literature [15, 16]. Contrarily to the literature, we found that kinetic curve is not related with c-erb B2 levels [16]. This situation can be explained by the minority of our population with a c-erb B2 data.
We cannot show any relationship between lesions’ diameters and kinetic curves. We also showed that a greater diameter is related with PR and ER absence. Our results are consistent with the literature [17]. Also, in the literature, it is stated that an augmented c-erb B2 causes the lesions to be greater in diameter, but we cannot show such a relationship [16].
In English literature, most of the studies found no relationship between CER and prognostic factors [18,19,20,21,22]; on the other hand, a more recent study defined a significant relationship with a high CER and high Ki-67 index [13]. In our study, we cannot demonstrate any relationship between CER and prognostic factors, in line with most of the previous studies.
Some studies showed that a high CER is related with the presence of an axillary pathological lymph node [19, 23], but we cannot find such a relationship in our study.
A low tpeak value is found to be related with some poor prognostic factors such as high histopathological grade, an augmented c-erb B2, ER absence, and a high Ki-67 index [6, 12, 24]. Also, maximum enhancement was found to be related with higher Ki-67 index [25]. We found a weak correlation between a low tpeak value and an augmented c-erb B2, but no relationship was found for other prognostic factors.
There are studies indicating a positive correlation between slopei value and histopathological grade, Ki-67 index [12, 25]. We cannot confirm these relationships in our study.
We found a relationship between the presence of axillary pathological lymph node and bigger lesion diameter, high histopathological grade, and high Ki-67 index, consistent with the literature [26, 27]. Also, absence of axillary pathological lymph node is found to be related with ER and PR presence, consistent with the literature [28, 29]. A weak relationship between axillary pathological lymph node presence and young patient age was detected. This is consistent with the readily known fact that early beginning breast cancers have poor prognosis [30].
Low ADC values were found to be related with the presence of axillary pathological lymph node in some studies, but there are also contradictory results [31, 32]. ADC values were found to be related with ER-negative and PR-negative status and a higher Ki-67 index [33, 34]. On the other hand, a recent study found no correlation between ADC values and ER, PR, and Ki-67 expression [35]. We cannot define any relationship between ADC values and histopathological prognostic markers.
Current study has some limitations: first of all the retrospective nature of the study. Secondarily, ADC values cannot be found for some of the patients. Also, we cannot reach the results of every prognostic markers for all patients, seeing that we cannot evaluate every prognostic factor in all patients.
Using different MRI devices and protocols cause different results about kinetic curves. This might be the cause of contradictory results between our study and literature, and among previous studies. Also there is not a standardized b value for ADC evaluation; these cause difficulties in comparing results of different studies. Twelve of 59 lesions of this study are smaller than 1 cm in diameter. For these kinds of lesions, 3-T MRI is better for evaluation. But our images were created by a 1.5-T MRI device. Insufficiency in patient number is another limitation. Larger and more homogenous populations may provide clearer results.