Survival Analysis of Breast Cancer in Patients with HER2/neu+, ER-, PR-: a Retrospective Cohort Study

Abstract

Aim: We aimed to study the characteristics of the breast cancer patients with positive HER2/neu+, ER- and PR- receptors. Methods: 119 patients with breast cancer were included in this retrospective cohort study from 2006 to 2016. The overall and disease-free survival were evaluated. Results: Most prevalent type of tumor was IDC, grade III cancer and stage II. Recurrence/metastasis occurred in 18.49%. Most common sites of metastasis were lungs and liver. Total mortality rate was 10.92%. Overall and disease-free survival times were 40.04 and 22.29 months, respectively. The median survival time was about 118 months. Conclusion: Breast cancers with positive HER2/neu and negative estrogen and progesterone receptors had low overall and disease-free survival rates compared with ER+/PR+/HER2- tumors.

Keywords: :

• biomarker
• breast cancer
• estrogen receptor
• HER2/neu
• progesterone receptor

Background

The second leading cause of cancer-related death in women is breast cancer, which is also the most common type of cancer in this demographic. Over 1.2 million cases of breast cancer are reported globally each year, and over 500,000 people pass away from the disease [1]. A study conducted in Iran from 2014 to 2016, revealed that female breast cancer affected 13,846 patients in Iran, and the crude and age-standardized incidence rates were 35.7 and 34.9 per 100,000 individuals, respectively [2]. Five-year survival rates are high in developed countries [3,4] but low in developing countries [5,6]. Prognostic factors for breast cancer include tumor size, number of involved lymph nodes, hormonal receptor status, lymph vascular invasion, cancer stage and metastasis presence. Also, the mutation in the BRCA1 and BRCA2 genes can cause breast cancer [3,4,7,8]. Certain biomarkers, including ki-67, the proliferating cell nuclear antigen (also known as cell proliferation factors), the expression of progesterone and estrogen receptors, HER2/neu amplification and extra-expression, c-Myc cycline, D1, p53 nuclear protein aggregation, Bcl expression and modifications to angiogenesis proteins such as vaso-endothelial growth factor, have also been introduced as prognostic factors [5,6,8,9]. The prognosis of breast cancer can be partially predicted by assessing the tumoral breast cells' rate of proliferation using various techniques, such as calculating the proportion of ki67 positive cells using IHC methods, indicating that faster-growing tumors have a worse prognosis. Scientists are currently attempting to define the behavior of the tumor in its early stages or tumors of the same stage by identifying the factors that affect the prognosis, even though tumor size and lymph node involvement remain the most important prognostic factors in breast cancer [10]. The presence of progesterone and estrogen receptors as well as increased HER2/neu expression are the most significant prognostic factors that influence treatment choices. The a2117 gene contains the proto-oncogene HER2/neu, which is in charge of producing the p185 HER2/neu protein, which has tyrosine kinase effects similar to those of EGF. Twenty to thirty% of breast cancers test positive for HER2/neu, which is linked to higher rates of tumor invasion, recurrence and death [5,8,11–14].

Objectives

In this study, we sought to address, based on cancer characteristics, the overall and disease-free survival (DFS) rate among patients with HER2/neu breast cancer who have negative estrogen and progesterone receptors.

Methods

All breast cancer patients referred to Rasool Akram Medical Complex and Khatam-al-Anbia Hospitals from March 2006 to March 2016, were enrolled in this study. Inclusion criteria were diagnosis of breast cancer via biopsy, positive Her2/neu and negative ER and PR receptors. A total of 119 patients met the inclusion criteria. Informed consent was obtained from the included patients before participating in the study. The study was performed in accordance with the ethical standards as laid down in the 1964 Declaration of Helsinki and its later amendments. The study was approved by the Ethic Committee of Iran University of Medical Sciences with the code number: IR.IUMS.FMD.REC.1398.030. In first step, all information regarding the patients' tumor type, treatment method was extracted from the patients' files. Also, clinical and pathologic characteristics of the tumor, including tumor size, lymph node involvement, primary metastasis and histologic grading were evaluated. The primary outcomes were recurrence and death. Patients who died of a non-cancer-related cause were excluded from the study. Then, information regarding the patients' mean age, grade of cancer, size of the tumor,%age of the sentinel lymph node, number of involved lymph nodes, stage of cancer at the time of diagnosis, degree of lymph vascular invasion (LVI), recurrence rate, presence of metastasis, mortality rate, overall survival and DFS rates were evaluated. Data analysis was performed using Stata 17. Continuous variables were described using mean ± SD, and categorical variables were described using frequency and%age. To assess the relationship between categorical variables, the Chi2 test was used. To assess the survival time and death, we used Kaplan Meier plots. Also, Cox regression was used for the evaluation of the survival rates. P-value less than 0.05 was assumed to be significant.

Results

A total of 119 female patients were included in this study. The mean age of the participants was 52.87 ± 11.71 years old. Most of the patients (36.97%) were in the age range of 50–59 years old. Invasive ductal carcinoma was the most common type (80.51%). The most common stage and grade at the time of diagnosis were stage II (41.9%), and grade III (52.78%). Most tumors were 2 to 3 cm in size (42.61%). Recurrence occurred in 6.73% of the patients and distal metastasis in 11.76% of the patients. The lungs and liver were the most common targets for distal metastasis (45.45%). Lymphovascular invasion was reported in 45.76% of the patients. Half of the patients had more than ten removed lymph nodes. Many of the removed lymph nodes were negative for cancer (51.75%). Sentinel node resection was performed in 61.8% of the patients and it was negative in many cases (67.12%). About 10% of the patients received neoadjuvant chemotherapy (Table 1).

Table 1. Characteristics of the patients with HER2+/ER-/PR- breast cancer (n = 119).

Variable		Frequency	Percentage
Age (year)	<30	1	0.84
	30–39	13	10.92
	40–49	30	25.21
	50–59	44	36.97
	60–69	20	16.81
	≥70	11	9.24
Type of cancer	Ductal carcinoma in situ	13	11.02
	Invasive ductal carcinoma	95	80.51
	Invasive lobular carcinoma	9	7.63
	Mixed invasive ductal lobular carcinoma	1	0.85
Stage	I	24	22.86
	II	44	41.90
	III	36	34.29
	IV	1	0.95
Grade	I	5	4.63
	II	46	42.59
	III	57	52.78
Tumor size (cm)	<2	33	28.70
	2–3	49	42.61
	>3 and ≤5	29	25.22
	>5	4	3.48
Recurrence	No	109	93.27
	Yes	8	6.73
Distal metastasis	No	105	88.24
	Yes	14	11.76
Site of metastasis/recurrence	Skin/breast (recurrence)	8	36.36
	Brain	2	9.09
	Bone	2	9.09
	Visceral (lungs and liver)	10	45.45
Lymph vascular involvement	No	64	54.24
	Yes	54	45.76
Number of removed lymph nodes	<10	57	50
	≥10	57	50
Number of positive nodes	N0	59	51.75
	N1 (1–3)	22	19.30
	N2 (4–9)	17	14.91
	N3 (≥10)	16	14.04
Sentinel node procedure	Yes	73	61.86
	No	45	38.14
Sentinel node result	Positive	24	32.88
	Negative	49	67.12

Mortality rate was the highest in the presence of brain metastasis (100%). Patients with the liver, lung and brain metastases had mortality rates of 80, 80 and 50%, respectively. Mortality rate was 25% among the patients with breast recurrence, and no mortality was reported in the patients with skin recurrence.

Overall survival time was 40.04 (SE: 8.16) months. DFS was 22.29 (SE: 4.51) months for patients suffering recurrence or metastasis. The median survival time was about 118 months.

Table 2 shows the risk of recurrence and mortality based on stage, grade, pathological type and neoadjuvant chemotherapy, and Table 3 shows the overall survival rate based on the location of the metastasis Also, Figures 1 & 2 represent the Kaplan Meier survival estimate for overall, DFS rates and overall death hazard rate.

Table 2. Risk of recurrence and death based on tumor characteristics, based on the univariate analysis.

	Variables	Recurrence		Mortality
		Hazard ratio	p-value	Hazard ratio	p-value
Stage	I	Reference	–	Reference	–
	II	0.81 (0.22–2.09)	0.75	1.07 (0.09–2.83)	0.09
	III	1.04 (0.29–3.06)	0.95	3.66 (2.06–5.49)	0.02
	IV	3.32 (0.36–1.41)	0.29	10.03 (0.2–14.49)	0.11
Grade	I	Reference	–	Reference	–
	II	0.51 (0.1–4.99)	0.3	0.43 (0.12–2.11)	0.36
	III	0.6 (0.26–2.13)	0.45	0.81 (0.18–7.04)	0.82
Pathological type	Ductal carcinoma in-situ	Reference	–	–	–
	Invasive ductal carcinoma	1.02 (0.91–7.12)	0.98	–	–
	Invasive lobular carcinoma	3(0.55–6.01)	0.23	–	–
	Mixed invasive ductal and lobular carcinoma	–	–	–	–
Neoadjuvant chemotherapy	No	Reference	0.3	Reference	0.001
	Yes	1.93 (0.90–2.04)		79.04 (61.11–83.70)
Mortality	No	Reference	0.26	–	–
	Yes	2.65 (0.28–3.23)

Table 3. Overall survival based on metastasis site.

Site of the metastasis	Overall survival, month
	Mean	SD	Min	Max
Local (skin/breast) metastasis	81.77	56.80	41.60	121.93
Brain metastasis	30.88	11.90	22.47	39.3
Bone metastasis	45.20	–	45.20	45.20
Lung and liver (visceral) metastasis	30.55	24.43	3.10	58.47

Figure 1. Overall survival of the patients with HER2/neu+, ER- and PR-breast cancer.

Figure 2. Disease-free survival of the patients with HER2/neu+, ER- and PR- breast cancer.

Discussion

Tumors presenting estrogen and progesterone receptors are known to be more differentiated, and to have a low pathological grade [15,16]. Lately, the HER2/neu genes have been introduced as the prognostic factors in breast cancer [17–20]. Earlier studies have reported bigger size and higher grades of the tumor, lymph node involvement and distant metastasis, lack of estrogen receptor, higher recurrence rates and poorer prognosis, in cases of amplified or excessive expression of the HER2/neu gene [21,22]. Also, excessive expression of the HER2/neu gene is useful in predicting the individual-based benefits of chemo or hormonal therapy [23–26]; however, these findings are still controversial [19,22].

We studied 119 patients with a mean age of 52.87 years old. Invasive ductal carcinoma was the most prevalent type of cancer being the primary diagnosis in 80.51% of the cases, supporting the findings of Moradi et al. [27], Nafissi [1] and Poorolajal [7] who studied all IHC subtypes of the breast cancer; meaning that the pathological type of the tumor did not differ between IHC subtypes of tumor (ER, PR, and HER2/neu receptors).

Most of our cases were diagnosed with stage II disease (41.9%) which is consistent with the findings in Fallah-Zade [28], Moradi [27] and Poorolajal's study [7].

Grade 3 tumor was the most prevalent type in our study, while grade II disease was the most prevalent tumor in Mirzaei [29], Poorolajal [7] and Moradi's studies [27]; indicating that HER2/neu+/ER-/PR- tumors can be less differentiated compared with all types of breast cancer.

In about 43% of the cases of our study, the tumor's size was 2–3 cm, which is in line with the findings of Mirzaei [29] and Moradi [27].

In our study, distant or local metastasis and recurrence occurred in 18.49 and 20% of the patients, respectively, which was slightly higher than Moradi's study that reported a metastasis rate of 10% [27]. Also, in the study of Poorolajal [7], distant metastasis occurred in 16.2% of the cases, and 14.2% of the patients showed evidence of recurrence in which many of the tumors were HER2/neu-/PR+ and ER+.

In the study of Akbari [30], loco-regional and distant metastasis occurred in 24.28%, and 67.09% of the cases, which is higher than the current study and other similar articles.

The liver and lungs were the most common sites of metastasis (45.45%). Skin and in-breast recurrence were seen in 36.36% of the cases. In the study of Akbari [30], bones were the most common site of distant metastasis (40.95%). These findings show that metastasis location may differ in different breast cancer IHC groups, although more thorough studies are needed in this matter.

Sixty-four percent of our patients had no lymphovascular invasion, which was pretty higher than Moradi's study reporting a 28% negative prevalence of LVI [27]. This finding indicated that HER2+/ER-/PR- tumors are less likely to cause LVI; noting that LVI has been associated with less DFS in previous studies [1,30]. This discordance in findings suggest that HER2+/ER-/PR- tumors may have higher DFS, although this finding should be interpreted together with other prognostic factors.

About 52% of the cases had no lymph node involvement, and in the involved case, mostly less than three lymph nodes were involved. In Mirzaei's study, most patients had more than four involved lymph nodes [29].

The mean DFS in the current study was 22.29 months. The mean survival rate in Moradi's study was 57 months being higher than our results [27]. In the study of Akbari, the mean DFS was 43.2 months [30]. However, the difference in the results mostly stem from the differences in study population or other prognostic factors; but still, the most important probable factors, in this case, are the IHC subtypes of breast cancer.

In the study of Poorolajal [7], the least survival time belonged to HER2+/ER-/PR- breast tumors. In the US [31–35], and other countries [36–39], racial differences have been introduced as factors affecting the prognostic genes' expression, and the mean survival rate, too.

The overall survival rate in this study was 40.04 months. The overall survival time was around 52 months in the study of Souvizi [40], and 58.9 months in the study of Moradi [27].

In the study of Nafissi et al. [1], the overall survival rate among the Iranian breast cancer population with HER2+/ER-/PR- during 10 years, was 43% which is similar to our findings, but it was 77–81% among all IHC subtypes of breast cancer-the least overall survival rate belonged to the HER2+/ER-/PR- subtype. These findings show that HER2+/ER-/PR- tumors have less overall and DFS.

The higher hazard ratio of mortality and recurrence attributed to higher stages and grades of the disease. In the study of Akbari et al. [30], higher stages and grades of breast cancer, and negative steroid receptors correlated with higher recurrence rates. Also, in the study of Souvizi [40], cancer stage was inversely correlated with overall survival (p = 0.00).

Invasive lobular carcinoma had a higher risk of recurrence than invasive ductal carcinoma.

Distant metastasis-especially to the brain- was related to death. In the study of Mendoza et al. [41], the survival time of metastatic breast cancer was as low as 18–24 months.

The use of neoadjuvant chemotherapy and Herceptin, which both have known effects on the breast cancer prognosis, was limited in Iran due to poor insurance coverage at the study time and this therapy was not used in many cases of our study; which may have affected the survival time, as well as uncertainty in the results showing that neoadjuvant therapy did not affect the recurrence and mortality rate might be due to that, although the overall findings of the study strongly support the idea of the poorer prognosis of the disease with HER2+/ER-/PR- IHC markers.

Moreover, the mean Ki67 was 30 ± 19.16, which was similar to the results of Sharifi et al.‘s study [42] but higher than other studies and this proliferative index may be influence less DFS in our study.

Conclusion

Based on our results, breast cancers with positive HER2/neu and negative estrogen and progesterone receptors have low overall and DFS rates compare to ER+/PR+/HER2- tumors. The risk of recurrence in invasive lobular carcinoma is higher than the invasive ductal carcinoma. Tumor stage, grade and the presence of distant metastasis are positively correlated with the risk of recurrence.

Summary points

• Our study aimed to examine breast cancer in 119 patients with positive HER2/neu and negative ER and PR receptors.

• These female patients had a mean age of 52.87 ± 11.74 years.

• The most common type of tumor was ‘invasive ductal carcinoma’ in pathology, with Grade III cancer and Stage II disease as the most common types.

• Approximately 18.49% of the patients have experienced metastasis in the lungs and liver.

• About 11 patients (10.92%) of the patients died. Overall and disease-free survival times were 40.04 and 22.29 months.

• Metastasis to the brain had the highest mortality rate.

• The risk of recurrence in invasive lobular carcinoma is higher than invasive ductal carcinoma.

• The median survival time was about 118 months.

• Breast cancers with positive HER2/neu and negative estrogen and progesterone receptors had low overall and disease-free survival rates compared with ER+/PR+/HER2- tumors.

Author contributions

P Amani and N Nafissi: conceptualization, data curation, formal analysis, investigation, visualization, methodology, writing – original draft, writing – review and editing. NM Hamidabad, A Negahi, L Shojaee and E Babaee: Investigation, writing – review and editing, analysis, investigation, data acquisition, writing – review, editing. All authors reviewed the manuscript.

Financial disclosure

The authors have no financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Writing disclosure

No writing assistance was utilized in the production of this manuscript.

Ethical conduct of research

All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1964 and later versions. This study was approved by the Ethic Committee of Iran University of Medical Sciences (IR.IUMS.FMD.REC.1398.030). In addition, for investigations involving human subjects, informed consent has been obtained from the participants involved.

Acknowledgments

The authors wish to thank Rasool Akram Medical Complex Clinical Research Development Center (RCRDC), Iran University of Medical Sciences for its data collection and editorial assistance.

Competing interests disclosure

The authors have no competing interests or relevant affiliations with any organization or entity with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.