Prognostic value of vitamin-D level in non-metastatic breast cancer patients in Saudi Arabia

Background: Deficiency of vitamin-D (Vit-D) was associated with poor survival outcome in several studies across different tumour types. The present study aims to assess the prevalence and prognostic value of Vit-D deficiency among breast cancer patients in a single institution in Saudi Arabia.

Methods: In this retrospective study, we screened patients who presented with non-metastatic breast cancer to King Abdullah Medical City,Saudi Arabia from June 2011 to December 2015. We checked baseline Vit-D level before starting systemic therapy in addition to other clinicopathological factors. Low Vit-D was defined as Vit-D level less than 30 ng /ml.The relations of Vit-D level (taking the median as the cutoff) with clinicopathological factors were assessed using Chi-Square test. Differences in survival outcome were compared using log rank test.

Results: We screened 340 patients with non-metastatic breast cancer. Baseline Vit-D levels were available for 189 patients. The median age was 50 years (range: 26- 86 years). Noteworthy, 169 (89.4%) of patients had Vit-D level <30 ng/ml with a median of 14.9 ng/ml (range: 4.0 - 45.0). Low Vit-D level (below the median) was significantly more common in premenopausal (p=0.011) and ER-negative patients (p=0.011). However, lymphovascular invasion (p=0.001),clinically (p=0.023) and pathologically positive axillary LNs (p=0.041) were linked with higher Vit- D level.After a median follow up period of 58.2 months, 14 patients died and 40 relapsed. The 5-year disease-free survival (DFS) rates was 74.8%. The 5-year DFS rate in patients with higher Vit-D level above the median was 78.8% compared to 71.1% in patients with lower Vit-D level with no statistically significance difference (p= 0.22). The 5-year overall survival (OS) rate was 90.2%. Meanwhile, no difference in 5-year OS rate in patients with higher and lower Vit-D levels (90.3% and 89.7% respectively, p=0.6).

Conclusion: Low Vit-D level was prevalent among the studied breast cancer patients. Low Vit-D level was associated with ER-negative phenotype and premenopausal patients. Baseline Vit-D level was not significantly linked with survival outcome.

 Introduction

Vitamin D (Vit-D) plays a vital role in calcium homeostasis, skeletal metabolism in addition to other vital physiological roles. Vit-D deficiency is a common health problem with numerous health consequences including osteomalacia, osteoporosis and fractures in adults [1].

Many reports showed an association between serum Vit-D deficiency and development of several types of cancer, including breast, colorectal, kidney and pancreatic cancers [2][3]. Several studies have confirmed that vitamin D receptors (VDR) are expressed in normal breast tissues and also in breast cancer biopsy specimens [4][5]. Noteworthy, Vit-D promotes apoptosis through the insulin-like growth factor receptor 1 (IGFR)- (PI3K)-Akt-dependent signaling pathway [3][4][5][6]. Therefore, deregulation of Vit-D signaling and related metabolic pathways was suggested to play an important role in tumour growth [7]. Meanwhile, large epidemiological studies suggested that Vit- D intake has a protective role against breast cancer development [8][9].

However, the prognostic value of VDR expression and circulating Vit-D level still remains controversial. Several studies reported that deficiency of Vit-D was associated with poor survival outcome across different tumour types while other studies reported different conclusions [10][11][12][13]. The present study aims to assess the prognostic value of Vit-D deficiency among non-metastatic breast cancer patients in a single institution in Saudi Arabia. This may give rise to an easy prognostic parameter that can be assessed in daily practice.

Materials and Methods Study population

Patients with histologically confirmed non-metastatic breast cancer who presented to King Abdullah Medical City, Saudi Arabia from June 2011 to December 2015, were included. Enrolled patients must have available baseline serum Vit-D level before starting any systemic therapy.

Study design and procedures

In this retrospective study, eligible patients must have adequate medical records. We checked baseline Vit-D level before starting systemic therapy in addition to other clinicopathological factors. Different parameters were collected including age, gender, stage at diagnosis, body mass index (BMI), pathological type, grade, ER, PR and HER2 status in addition to treatment data including type and number of chemotherapy cycles, hormonal therapy and trastuzumab (if applicable). Dates of disease relapse and death if any, were recorded.

 Statistical analysis

SPSS version 21 statistical program was used. Descriptive statistics were performed for all clinical, laboratory and pathological data. Low Vit-D was defined as Vit-D level less than 30 ng /ml. The relations of Vit-D level (taking 30 ng/ ml and the median as the cutoffs) with clinico-pathological factors were assessed using Chi-Square test. Different potential prognostic factors were assessed in relation with disease free survival (DFS) and overall survival (OS). Survival data was presented by Kaplan Meier method where cases with no recorded events (death or relapse) were censored at the date of last contact. Comparisons of survival outcome among different parameters were assessed using the log rank test. A two-sided alpha was set at 0.05. DFS was defined as the time from date of breast surgery to date of documented tumour relapse or death. OS was defined as the time from the date of diagnosis of breast cancer till the date of death.

 Results Patients’ and tumor characteristics

We screened 340 patients with non-metastatic breast cancer. Baseline Vit-D levels were available for 189 patients with a median level of 14.9 ng/ml (range: 4.0 - 45.0). Noteworthy, 169 (89.4%) of patients had Vit-D level <30 ng/ml. Using 30 ng/ml as the cutoff, there was no significant association between different parameters and Vit-D level. We therefore, used the median Vit-D level as the cutoff to have enough patients for comparison. The median age was 50 years (range: 26- 86 years) and it was significantly lower in patients with lower compared to higher Vit-D levels (47 vs. 51 years respectively, p=0.04). Similarly, Low Vit-D level (below the median) was significantly more common in premenopausal compared to postmenopausal patients (59.4%, 40.9%, respectively, p=0.01) and ER-negative vs. positive patients (63.1% vs 43.5%, respectively, p=0.01). However, lymphovascular invasion (LVI) (72.2% vs. 27.8%, p=0.001), clinically (62.5% vs. 37.5% respectively, p=0.02) and pathologically positive axillary LNs (p=0.04) were linked with higher Vit- D level. However, other clinicopathological factors did not significantly differ according to Vit-D level (Table 1).

<bold id="bold-cbacbf2e716b755bdad55d54e66453b0"></bold>

Parameters

Total=189

No

Vitamin D <median

No (%)

Vitamin D ≥median

No (%)

P

Median age (range)

50 (26-86)

 47 (26-76) 51 (31-86) 0.04

Menopausal status

Premenopausal

96

57 (59.4)

39 (40.6)

 0.01
Postmenopausal 93 38 (40.9) 55 (59.1)
Body mass index
<25 19 13 (68.4) 6 (31.6)
25-29.9 69 31 (44.9) 38 (55.1) 0.25
30-39.9 79 38 (48.1) 41 (51.9)
≥40 22 13 (59.1) 9 (40.9)
Pathology
IDC 178 89 (50.0) 89 (50.0) 0.07
ILC 7 2 (28.6) 5 (71.4)
Other 4 4 (100.0) 0 (0.0)
Grade
Grade 1 11 8 (72.7) 3 (27.3)
Grade 2 104 51 (49.0) 53 (51.0) 0.07
Grade 3 63 34(54.0) 29 (46.0)
Unknown 11 2 (18.2) 9 (81.8)
Lymphovascular invasion
Yes 54 15 (27.8) 39 (72.2) <0.001
No 127 76 (59.8) 51 (40.2)
ER status
Negative 65 41 (63.1) 24 (36.9)
Positive 124 54 (43.5) 70 (56.5) 0.01
PR Status
Negative 82 46 (56.1) 36 (43.9) 0.16
Positive 107 49 (45.8) 58 (54.2)
HER2 status
Negative 124 62 (50.0) 62 (50.0)
Positive 62 33 (53.2) 29 (46.8) 0.19
Unknown 3 0 (0.0) 3 (100.0)
Clinical Stage
Stage I 20 12 (60.0) 8 (40.0)
Stage II 88 41 (46.6) 47 (53.4)
Stage IIIA 52 30 (57.7) 22 (42.3) 0.42
Stage IIIB 17 6 (35.3) 11 (64.7)
Unknown 12 6 (50.0) 6 (50.0)
Clinical T stage
Tx 13 8 (61.5) 5 (38.5)
T0 9 4 (44.4) 5 (55.6)
T1 32 18 (56.3) 14 (43.8) 0.18
T2 80 34 (42.5) 46 (57.5)
T3 28 18 (64.3) 10 (35.7)
T4 11 3 (27.3) 8 (72.7)
Clinical LN status
Negative 65 38 (58.5) 27 (41.5)
Positive 72 27(37.5) 45 (62.5) 0.02
Nx 52 30 (57.7) 22 (42.3)
Pathological N
Nx 5 1 (20.0) 4 (80.0)
N0 91 54 (59.3) 37 (40.7)
N1 49 18 (36.7) 31 (63.3) 0.04
N2 28 16 (57.1) 12 (42.9)
N3 16 6 (37.5) 10 (62.5)
Relapse
Yes 40 23 (57.5) 17 (42.5) 0.30
No 149 72 (48.3) 77 (51.7)
Survival outcome

After a median follow up period of 58.2 months, 14 patients died and 40 relapsed. No difference in the rate of relapse between patients with lower vs. higher Vit-D level using different cutoffs, (Table 1). The 5-year DFS rate was 74.8%. Using 30 ng/ml as the cutoff, no difference in DFS between higher and lower Vit-D levels (73.5% vs. 75%, p=0.38) was found. Using the median as the cutoff, the 5-year DFS rates were 78.8% vs. 71.1%, in patients with higher compared to lower Vit-D levels, respectively. However, it did not reach statistical significance (p= 0.22) (Figure 1).

Lower clinical (p=0.001) and pathological stages (stage I, II) (0.001) and higher BMI (p=0.04) were the only factors associated with better DFS rates. Other clinico-pathological parameters were not linked with DFS outcome (Table 2).

<bold id="bold-81476b99543b030288eeec17fbf0d1e4"></bold>

Parameters

Total=189

No

5-year DFS

(%)

P

Body mass index
<25 19 81.7%
25-29.9 69 63.2% 0.04
30-39.9 79 82.6%
≥40 22 79.5%
Menopausal status
Premenopausal 96 70.4% 0.27
Postmenopausal 93 78.9%
Clinical Stage
Stag I-II 108 83.0% 0.001
Stage III 69 66.1%
Clinical T
T0-2 121 80.6% <0.001
T3-4 39 58.9%
Clinical LN status
Negative 65 77.1%
Positive 72 74.2% 0.70
Nx 52 74.0%
Pathology
IDC 178 74.6%
ILC 7 60.0% 0.42
Other 4 100.0%
Multicentricity
Yes 26 61.7% 0.22
No 163 76.5%
Lymphovascular invasion
Yes 54 69.1%
No 127 77.1% 0.11
Grade
Grade 1 11 66.7%
Grade 2 104 74.2% 0.51
Grade 3 63 80.8%
Unknown 11 62.3%
ER status
Negative 65 70.8 % 0.18
Positive 124 76.7 %
PR Status
Negative 82 72.3 % 0.40
Positive 107 76.5 %
HER2 status
Negative 124 77.9 %
Positive 62 70.1 % 0.28
Unknown 3 0.00 %
Pathological T
T0-2 159 76.2% 0.44
T3-4 24 65.2%
Pathological N
N0 91 86.8 % 0.001
N+ 93 62.3%
Pathologic Stage
Stage 0-II 130 79.6 % 0.02
Stage III 57 65.2%
Chemotherapy cycles Number
≤6 74 70.6 % 0.67
>6 91 74.3 %
Chemotherapy Type
Anthracycline & Taxane 135 70.9 %
Anthracycline only 23 78.3% 0.69
Taxane only 7 83.3%
Vitamin D
<median 95 71.1% 0.22
≥ median 94 78.8%

The 5-year OS rate was 90.2%. Using 30 ng/ml as the cutoff, no difference in OS between higher and lower Vit-D levels (93.5% vs. 85%, p=0.09) was found. Similarly, using the median as the cutoff, no difference in 5-year OS rate in patients with higher and lower Vit-D levels (90.3% and 89.7% respectively, p=0.6) (Figure 2).

OS was significantly higher in patients with lower pathologic stage (stage I, II), (p= 0.006). Meanwhile, no difference in OS outcome according to other clinico-pathological factors (Table 3).

<bold id="bold-33e1517a10f006079b92e1f5b713dace"></bold>

Parameters

Total

189

5-year OS

(%)

P

Body mass index
<25 19 92.9%
25-29.9 69 85.3% 0.17
30-39.9 79 91.2%
≥40 22 100.0%
Body mass index
<30 88 86.7% 0.06
≥ 30 101 93.0%
Clinical Stage
Stag I-II 108 92.0% 0.16
Stage III 69 87.2%
Pathology
IDC 178 91.1%
ILC 7 53.3% 0.05
Other 4 100.0%
Menopausal status
Premenopausal 96 86.6% 0.18
Postmenopausal 93 93.4%
Clinical T
T0-2 121 92.8% 0.17
T3-4 39 87.3%
Lymphovascular invasion
Yes 54 85.9% 0.13
No 127 92.2%
Grade
Grade 1 11 100.0%
Grade 2 104 87.0% 0.52
Grade 3 63 94.9%
Unknown 11 87.5%
Clinical LN status
Negative 65 91.3%
Positive 72 89.0% 0.79
Nx 52 91.0%
ER status
Negative 65 86.8 % 0.13
Positive 124 91.8 %
PR Status
Negative 82 87.6 % 0.21
Positive 107 91.8 %
HER2 status
Negative 124 93.3 %
Positive 62 85.9 % 0.14
Unknown 3 0.00 %
Pathological T
T0-2 159 91.1 % 0.22
T3-4 24 85.7 %
Pathological N
N0 91 94.0 % 0.09
N+ 93 87.5 %
Pathologic Stage
Stage 0-II 130 94.0 % 0.01
Stage III 57 82.9 %
Chemotherapy
Yes 165 90.4 % 0.95
No 24 86.3 %
Chemotherapy cycles Number
≤6 74 90.4 % 0.87
>6 91 90.5 %
Chemotherapy Type
Anthracycline & Taxane 135 89.0%
Anthracycline only 23 95.0% 0.61
Taxane only 7 100.0%
Vitamin D
<median 95 89.7 % 0.60
≥ median 94 90.3 %
Discussion

In this study, we assessed the prognostic value of baseline Vit-D level in a cohort of early breast cancer patients in a single institution in Saudi Arabia. Noteworthy, the great majority of patients (89%) had low Vit-D level below the reference value and even half of the patients had considerably low values (< 14 ng/ml).This highlights the prevalence of low Vit-D levels among Saudi patients with a median age of 50 years. This points to the magnitude of the problem of low Vit-D even among this cohort of generally young healthy patients in Saudi Arabia.

Noteworthy, lower Vit-D level was significantly linked with ER-negative phenotype and premenopausal status, features generally linked with more aggressive tumour behavior. Meanwhile, higher Vit-D values were linked with clinically and pathologically-positive lymph nodes and lymphovascular invasion. This conflicting data highlights the need to explore those findings in a larger cohort of patients.

Several studies reported an association between Vit-D deficiency and poor survival. In a prospective study including 512 patients with early breast cancer, low Vit-D was significantly linked with the risk of distant recurrence and overall survival [11]. Similarly, low Vit-D level was significantly associated with poor OS and DFS in a larger cohort of 1,295 postmenopausal breast cancer patients [13]. However, despite the fact that several epidemiologic and clinical studies suggested that Vit- D deficiency may be associated with breast cancer outcome, other studies did not display any association. This may be attributed to timing of measurement of the vitamin D, stage, menopausal status and hormonal receptor status [14]. Noteworthy, the association of Vit-D level and survival outcome were assesses in two meta-analyses, involving 8 and 5 studies. These meta-analyses showed an association of low Vit-D level with recurrence in addition to overall and breast cancer-specific mortality in breast cancer patients [15][16].

In our study, Vit-D level was not linked with survival outcome. Meanwhile, almost all patients with low Vit-D, received calcium and Vit-D supplementation later on in their disease course, which may mitigate or modulate any potential prognostic value. Furthermore, only 10% of patients had normal Vit-D levels above the reference value which limits the validity of comparing the survival outcome of low vs. normal Vit-D levels in our study. Meanwhile, there was a trend towards improved DFS in those with higher Vit-D level taking the median as the cutoff. However, that analysis was actually comparing low vs. higher (but still almost lower than normal value). Furthermore, only 14 patients died among the study population, which limits assessment of OS as data is still immature for OS comparison.

In conclusion, low Vit-D level was prevalent among the studied breast cancer patients. Low Vit-D level was associated with ER-negative phenotype and premenopausal patients. Baseline Vit-D level was not significantly linked with survival outcome.

 Acknowledgements

-This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

-The authors declare no conflict of interest.

 References 01 117822341774981 11 2017 10.1177/1178223417749816 Atoum Manar Alzoughool Foad Breast Cancer: Basic and Clinical Research Vitamin D and Breast Cancer: Latest Evidence and Future Steps 16 3 07 129-137 22 2015 10.3727/096504015x14267282610894 Wu Xiayu Zhou Tao Cao Neng Ni Juan Wang Xu Oncology Research Featuring Preclinical and Clinical Cancer Therapeutics Role of Vitamin D Metabolism and Activity on Carcinogenesis 9 09 684-700 7 2007 10.1038/nrc2196 Deeb Kristin K. Trump Donald L. Johnson Candace S. Nature Reviews Cancer Vitamin D signalling pathways in cancer: potential for anticancer therapeutics 1677 1681 44 1984 Freake HC Abeyasekera G Iwasaki J Marcocci C MacIntyre I et al Cancer Res Measurement of 1,25-dihydroxyvitamin D3 receptors in breast cancer and their relationship to biochemical and clinical indices 31 3 05 14 2012 10.1186/bcr3178 Lopes Nair Paredes Joana Costa José Luis Ylstra Bauke Schmitt Fernando Breast Cancer Research Vitamin D and the mammary gland: a review on its role in normal development and breast cancer 09 4 08 457-463 79 2013 10.1111/cen.12268 Ameri Pietro Giusti Andrea Boschetti Mara Murialdo Giovanni Minuto Francesco Ferone Diego Clinical Endocrinology Interactions between vitamin D and IGF-I: from physiology to clinical practice 11 9 08 1215-1227 16 2011 10.1634/theoncologist.2011-0098 Buttigliero C. Monagheddu C. Petroni P. Saini A. Dogliotti L. Ciccone G. Berruti A. The Oncologist Prognostic Role of Vitamin D Status and Efficacy of Vitamin D Supplementation in Cancer Patients: A Systematic Review 24 8 03 2590-2599 19 2012 10.1245/s10434-012-2297-3 Peppone Luke J. Rickles Aaron S. Janelsins Michelle C. Insalaco Michael R. Skinner Kristin A. Annals of Surgical Oncology The Association Between Breast Cancer Prognostic Indicators and Serum 25-OH Vitamin D Levels 1 8390 2 2009 10.4076/1757-1626-2-8390 Rainville Christa Khan Yasir Tisman Glenn Cases Journal Triple negative breast cancer patients presenting with low serum vitamin D levels: a case series 29 1 06 34-39 71 2017 10.1136/jclinpath-2016-204222 Soljic Martina Mrklic Ivana Tomic Snjezana Omrcen Tomislav Sutalo Nikica Bevanda Milenko Vrdoljak Eduard Journal of Clinical Pathology Prognostic value of vitamin D receptor and insulin-like growth factor receptor 1 expression in triple-negative breast cancer 10 23 08 3757-3763 27 2009 10.1200/jco.2008.20.0725 Goodwin Pamela J. Ennis Marguerite Pritchard Kathleen I. Koo Jarley Hood Nicky Journal of Clinical Oncology Prognostic Effects of 25-Hydroxyvitamin D Levels in Early Breast Cancer 14 7 12 1830-1836 18 2010 10.1245/s10434-010-1465-6 Kim Hee Jeong Lee Yu Mi Ko Beon Seok Lee Jong Won Yu Jong Han Son Byung Ho Gong Gyung-Yub Kim Sung Bae Ahn Sei Hyun Annals of Surgical Oncology Vitamin D Deficiency is Correlated with Poor Outcomes in Patients with Luminal-type Breast Cancer 26 4 07 13 2011 10.1186/bcr2920 Vrieling Alina Hein Rebecca Abbas Sascha Schneeweiss Andreas Flesch-Janys Dieter Chang-Claude Jenny Breast Cancer Research Serum 25-hydroxyvitamin D and postmenopausal breast cancer survival: a prospective patient cohort study 2 02 19 2018 10.22034/APJCP.2018.19.2.571 Ismail Abeer El Awady Rehab Abdelsalam Ghada Hussein Marwa Ramadan Shimaa Asian Pacific Journal of Cancer Prevention Prognostic Significance of Serum Vitamin D Levels in Egyptian Females with Breast Cancer 07 12 12 2972-2983 134 2013 10.1002/ijc.28628 Vrieling Alina Seibold Petra Johnson Theron S. Heinz Judith Obi Nadia Kaaks Rudolf Flesch-Janys Dieter Chang-Claude Jenny International Journal of Cancer Circulating 25-hydroxyvitamin D and postmenopausal breast cancer survival: Influence of tumor characteristics and lifestyle factors? 8 05 1510-1521 50 2014 10.1016/j.ejca.2014.02.006 Maalmi Haifa Ordóñez-Mena José Manuel Schöttker Ben Brenner Hermann European Journal of Cancer Serum 25-hydroxyvitamin D levels and survival in colorectal and breast cancer patients: Systematic review and meta-analysis of prospective cohort studies