There is 4 patient that did not consent and removed (not included in the total).

Note: Of 2859 total survey respondents, 1972 had complete data on 12 key variables (Consent, received germline genetic testing, genetic diagnosis, age at diagnosis (germline mutation), genetic test result, sex at birth, age range, cancer diagnosis, family history of stomach cancer, any gastric lesion, race/ethnicity, anti-acid medication/proton pump inhibitors). We proceed our analysis with n=1972 patients.

Figures

Self-reported cancer diagnosis. Note patients may indicate more than one cancer.

## All reported carrying a pathogenic or likely pathogenic variant.

Self-reported race/ethnicity. Note patients may report more than one race/ethnicity.

Self-reported genes. Note patients may report more than one gene.

Self-reported genes among Stomach cancer patients. Note patients may report more than one gene.

Self-reported gastric lesions. Note patients may report more than one lesion.

Table 1. Overall demographics and health characteristics

Characteristic N = 1,9721
Age
    Less than 29 53 (2.7%)
    30-39 206 (10%)
    40-49 445 (23%)
    50-59 495 (25%)
    60-69 490 (25%)
    70 and over 282 (14%)
    Missing 1
Sex
    Female 1,880 (95%)
    Male 92 (4.7%)
Race_Ethnicity
    American Indian, Alaska Native, or First Nations 1 (<0.1%)
    Asian or Asian American 29 (1.5%)
    Black or African-American 13 (0.7%)
    Hispanic White 21 (1.1%)
    Hispanic, Latino, or Latinx 47 (2.4%)
    Mixed race/ethnicity 28 (1.4%)
    Non-Hispanic White 1,812 (92%)
    Other 21 (1.1%)
Any_Gastric_Lesion 976 (49%)
H_pylori 135 (6.8%)
Fam_Hist_Stomach_Cancer
    Don't know 332 (17%)
    No 1,139 (58%)
    Yes 501 (25%)
Stomach_Cancer 51 (2.6%)
1 n (%)

Table 2. Risk factors by any gastric lesion

Any grastric lesion includes any of the following:

  1. Helicobacter Pylori (H. pylori)

  2. Gastritis

  3. Gastric Ulcer

  4. Gastro-esophageal reflux (GERD)

  5. Intestinal Metaplasia

  6. Barrett’s Esophagus

  7. Pernicious Anemia

HR genes: ATM, BARD1, BRCA1, BRCA2, BRIP1, CHEK2, PALB2, RAD51C, RAD51D, NBN

Lynch genes: MLH1, MSH2, MSH6, PMS2, EPCAM

Hereditary Diffuse Gastric Cancer (HDGC) genes: CDH1, CTNNA1

Juvenile Polyposis Syndrome genes: SMAD4, BMPR1A

Peutz-Jeghers Syndrome gene: STK11 (also known as LKB1)

Li-Fraumeni Syndrome gene: TP53

Recessive cancer predisposition syndrome genes: MUTYH, NTHL1

All other genes not included: CDKN2A, ENG, NF1, PTEN

Table 3. Overall Germline Mutation Carriers (by H. pylori)

Characteristic N = 1,9721
Stomach_Cancer
    No 1,921 (97%)
    Yes 51 (2.6%)
H_pylori
    No 1,837 (93%)
    Yes 135 (6.8%)
Anti_acid_ever
    No 859 (44%)
    Yes 1,113 (56%)
1 n (%)
Characteristic N = 1,9721
HR
    No 436 (22%)
    Yes 1,536 (78%)
Lynch
    No 1,620 (82%)
    Yes 352 (18%)
HDGC
    No 1,891 (96%)
    Yes 81 (4.1%)
FAP
    No 1,935 (98%)
    Yes 37 (1.9%)
Juvenile_Polyposis_Syndrome
    No 1,969 (100%)
    Yes 3 (0.2%)
Peutz_Jeghers_Syndrome
    No 1,964 (100%)
    Yes 8 (0.4%)
Li_Fraumeni_Syndrome
    No 1,962 (99%)
    Yes 10 (0.5%)
Recessive_Cancer_Predisposition
    No 1,951 (99%)
    Yes 21 (1.1%)
Other_genes
    No 1,972 (100%)
1 n (%)
Characteristic Overall
N = 1,972
1
No
N = 1,837
1
Yes
N = 135
1
p-value
HR


0.42
    No 436 (22%) 410 (22%) 26 (19%)
    Yes 1,536 (78%) 1,427 (78%) 109 (81%)
Lynch


0.82
    No 1,620 (82%) 1,510 (82%) 110 (81%)
    Yes 352 (18%) 327 (18%) 25 (19%)
HDGC


0.52
    No 1,891 (96%) 1,760 (96%) 131 (97%)
    Yes 81 (4.1%) 77 (4.2%) 4 (3.0%)
FAP


0.53
    No 1,935 (98%) 1,801 (98%) 134 (99%)
    Yes 37 (1.9%) 36 (2.0%) 1 (0.7%)
Juvenile_Polyposis_Syndrome


0.23
    No 1,969 (100%) 1,835 (100%) 134 (99%)
    Yes 3 (0.2%) 2 (0.1%) 1 (0.7%)
Peutz_Jeghers_Syndrome


>0.93
    No 1,964 (100%) 1,829 (100%) 135 (100%)
    Yes 8 (0.4%) 8 (0.4%) 0 (0%)
Li_Fraumeni_Syndrome


0.0263
    No 1,962 (99%) 1,830 (100%) 132 (98%)
    Yes 10 (0.5%) 7 (0.4%) 3 (2.2%)
Recessive_Cancer_Predisposition


>0.93
    No 1,951 (99%) 1,817 (99%) 134 (99%)
    Yes 21 (1.1%) 20 (1.1%) 1 (0.7%)
Other_genes



    No 1,972 (100%) 1,837 (100%) 135 (100%)
1 n (%)
2 Pearson’s Chi-squared test
3 Fisher’s exact test

Table 4. Cancers by family history of gastric cancer

Note: n=332 who responded “Don’t know” are not included in table 4.

Table 5. Risk factors by gastric cancer status

Characteristic Overall
N = 944
1
No
N = 893
1
Yes
N = 51
1
p-value
Fam_Hist_Stomach_Cancer


<0.0012
    Don't know 140 (15%) 134 (15%) 6 (12%)
    No 552 (58%) 533 (60%) 19 (37%)
    Yes 252 (27%) 226 (25%) 26 (51%)
Any_Gastric_Lesion


0.0442
    No 481 (51%) 462 (52%) 19 (37%)
    Yes 463 (49%) 431 (48%) 32 (63%)
H_pylori


0.0653
    No 890 (94%) 845 (95%) 45 (88%)
    Yes 54 (5.7%) 48 (5.4%) 6 (12%)
HR


<0.0012
    No 211 (22%) 182 (20%) 29 (57%)
    Yes 733 (78%) 711 (80%) 22 (43%)
Lynch


0.72
    No 799 (85%) 755 (85%) 44 (86%)
    Yes 145 (15%) 138 (15%) 7 (14%)
HDGC


<0.0013
    No 886 (94%) 855 (96%) 31 (61%)
    Yes 58 (6.1%) 38 (4.3%) 20 (39%)
Anti_acid_ever


>0.92
    No 393 (42%) 372 (42%) 21 (41%)
    Yes 551 (58%) 521 (58%) 30 (59%)
Anti_acid_time



    No 393 (42%) 372 (42%) 21 (42%)
    Daily 205 (22%) 185 (21%) 20 (40%)
    1-4 times weekly 136 (14%) 136 (15%) 0 (0%)
    1-4 times monthly 54 (5.7%) 52 (5.8%) 2 (4.0%)
    1-4 times in past 6 months 118 (13%) 115 (13%) 3 (6.0%)
    Other/As needed 37 (3.9%) 33 (3.7%) 4 (8.0%)
    Missing 1 0 1
1 n (%)
2 Pearson’s Chi-squared test
3 Fisher’s exact test

Let’s look at cell counts for (gastic cancer/no cancer), H pylori, and HR

##                              HR  No Yes
## Stomach_ORNO_Cancer H_pylori           
## No                  No          173 672
##                     Yes           9  39
## Yes                 No           27  18
##                     Yes           2   4

Table 6. Risk factors by (gastric cancer or any gastric lesion)

Cases: Gastric cancer, or any gastric lesion

Controls: (Non-gastric cancer and no family history of gastric cancer) or no cancer

Note we are assuming comparability of groups.

Characteristic Overall
N = 1,457
1
0
N = 462
1
1
N = 995
1
p-value
H_pylori


<0.0012
    No 1,322 (91%) 462 (100%) 860 (86%)
    Yes 135 (9.3%) 0 (0%) 135 (14%)
Anti_acid_ever


<0.0012
    No 507 (35%) 275 (60%) 232 (23%)
    Yes 950 (65%) 187 (40%) 763 (77%)
HR


<0.0012
    No 355 (24%) 77 (17%) 278 (28%)
    Yes 1,102 (76%) 385 (83%) 717 (72%)
Lynch


<0.0012
    No 1,179 (81%) 400 (87%) 779 (78%)
    Yes 278 (19%) 62 (13%) 216 (22%)
HDGC


0.0112
    No 1,385 (95%) 449 (97%) 936 (94%)
    Yes 72 (4.9%) 13 (2.8%) 59 (5.9%)
FAP


0.62
    No 1,429 (98%) 452 (98%) 977 (98%)
    Yes 28 (1.9%) 10 (2.2%) 18 (1.8%)
Juvenile_Polyposis_Syndrome


0.63
    No 1,454 (100%) 462 (100%) 992 (100%)
    Yes 3 (0.2%) 0 (0%) 3 (0.3%)
Peutz_Jeghers_Syndrome


0.33
    No 1,453 (100%) 462 (100%) 991 (100%)
    Yes 4 (0.3%) 0 (0%) 4 (0.4%)
Li_Fraumeni_Syndrome


0.113
    No 1,450 (100%) 462 (100%) 988 (99%)
    Yes 7 (0.5%) 0 (0%) 7 (0.7%)
Recessive_Cancer_Predisposition


0.23
    No 1,443 (99%) 460 (100%) 983 (99%)
    Yes 14 (1.0%) 2 (0.4%) 12 (1.2%)
Stomach_Genes


0.0502
    No 40 (2.7%) 7 (1.5%) 33 (3.3%)
    Yes 1,417 (97%) 455 (98%) 962 (97%)
Other_genes



    No 1,457 (100%) 462 (100%) 995 (100%)
1 n (%)
2 Pearson’s Chi-squared test
3 Fisher’s exact test

Table 7. Associations between cancer-predisposing gene groups and risk for (gastric cancer or any gastric lesion).

Models are adjusted for sex and current age category. 95% CI uses the profile likelihood method.

Gene No cancer/Non-gastric cancer & No family history n=462 Gastric/Lesion n=995 OR (95% CI) P-Value
HRYes 385 (83.33) 717 (72.06) 0.42 (0.31-0.57) 0.0000000
LynchYes 62 (13.42) 216 (21.71) 1.94 (1.41-2.69) 0.0000549
HDGCYes 13 (2.81) 59 (5.93) 2.65 (1.46-5.17) 0.0024257
FAPYes 10 (2.16) 18 (1.81) 1.13 (0.51-2.64) 0.7625385
Recessive_Cancer_PredispositionYes 2 (0.43) 12 (1.21) 2.58 (0.66-17.15) 0.2311831
Stomach_GenesYes 455 (98.48) 962 (96.68) 0.32 (0.13-0.71) 0.0090270
BRCA1Yes 100 (21.65) 162 (16.28) 0.67 (0.5-0.9) 0.0080338
BRCA2Yes 161 (34.85) 228 (22.91) 0.53 (0.41-0.68) 0.0000009
CDH1Yes 13 (2.81) 56 (5.63) 2.5 (1.37-4.89) 0.0046260
H_pyloriYes 0 (0) 135 (13.57) 19963182.28 (1.85953575363393e+22-1.283383537954e+64) 0.9590525

Looking at gastric risk scores

Interaction effects - (Unable to do, 0 cell)

Parameter Odds Ratio SE 95% CI z p
HR (Yes) 0.40 0.06 (0.29, 0.54) -5.98 < .001
H pylori (Yes) 1.12e+07 8.35e+09 (0.00, Inf) 0.02 0.983
HR (Yes) × H pylori (Yes) 2.14 1776.37 (0.00, Inf) 9.20e-04 > .999

Table 8. Stomach Cancer: Interaction effects of HR and HDGC genes with H. pylori any gastric lesion

Models adjusted for sex and entry age category. 95% CI uses the profile likelihood method. Note that interaction analysis is likely underpowered due to low n=51 stomach cases.

8a. HR x H. pylori

##              Stomach_ORNO_Cancer  No Yes
## HR  H_pylori                            
## No  No                           173  27
##     Yes                            9   2
## Yes No                           672  18
##     Yes                           39   4
Parameter Odds Ratio SE 95% CI z p
HR (Yes) 0.15 0.05 (0.08, 0.29) -5.72 < .001
H pylori (Yes) 1.50 1.26 (0.21, 6.65) 0.48 0.631
HR (Yes) × H pylori (Yes) 2.42 2.48 (0.34, 22.09) 0.86 0.389

8b. HR x any gastric lesion

##                        Stomach_ORNO_Cancer  No Yes
## HR  Any_Gastric_Lesion                            
## No  No                                      77  13
##     Yes                                    105  16
## Yes No                                     385   6
##     Yes                                    326  16
Parameter Odds Ratio SE 95% CI z p
HR (Yes) 0.08 0.04 (0.03, 0.23) -4.73 < .001
Any Gastric Lesion (Yes) 0.86 0.36 (0.38, 1.96) -0.37 0.710
HR (Yes) × Any Gastric Lesion (Yes) 3.33 2.14 (0.97, 12.28) 1.87 0.061

8c. HDGC x H. pylori

##               Stomach_ORNO_Cancer  No Yes
## HDGC H_pylori                            
## No   No                           807  25
##      Yes                           48   6
## Yes  No                            38  20
##      Yes                            0   0
Parameter Odds Ratio SE 95% CI z p
HDGC (Yes) 18.69 6.94 (9.04, 39.05) 7.89 < .001
H pylori (Yes) 3.98 1.94 (1.40, 9.78) 2.83 0.005

8d. HDGC x any gastric lesion

##                         Stomach_ORNO_Cancer  No Yes
## HDGC Any_Gastric_Lesion                            
## No   No                                     449   6
##      Yes                                    406  25
## Yes  No                                      13  13
##      Yes                                     25   7
Parameter Odds Ratio SE 95% CI z p
HDGC (Yes) 87.29 53.08 (27.76, 308.66) 7.35 < .001
Any Gastric Lesion (Yes) 4.37 2.02 (1.88, 11.91) 3.19 0.001
HDGC (Yes) × Any Gastric Lesion (Yes) 0.05 0.04 (0.01, 0.24) -3.71 < .001

Table 9. Colorectal Cancer: Interaction effects of HR and Lynch genes with H. pylori

Models adjusted for sex and entry age category. 95% CI uses the profile likelihood method. Note that interaction analysis is likely underpowered due to low n=88 colorectal cases. There are cells with 0 value.

9a. HR x H. pylori

## , ,  = No
## 
##      
##         No  Yes
##   No   356   22
##   Yes 1404  102
## 
## , ,  = Yes
## 
##      
##         No  Yes
##   No    54    4
##   Yes   23    7
Parameter Odds Ratio SE 95% CI z p
HR (Yes) 0.09 0.02 (0.05, 0.15) -9.16 < .001
H pylori (Yes) 1.14 0.67 (0.31, 3.28) 0.22 0.824
HR (Yes) × H pylori (Yes) 3.54 2.62 (0.85, 16.35) 1.71 0.087

9b. Lynch x H. pylori

## , ,  = No
## 
##      
##         No  Yes
##   No  1485  108
##   Yes  275   16
## 
## , ,  = Yes
## 
##      
##         No  Yes
##   No    25    2
##   Yes   52    9
Parameter Odds Ratio SE 95% CI z p
Lynch (Yes) 12.22 3.17 (7.43, 20.61) 9.66 < .001
H pylori (Yes) 1.02 0.76 (0.16, 3.54) 0.03 0.976
Lynch (Yes) × H pylori (Yes) 3.19 2.81 (0.66, 23.90) 1.32 0.187
##                                                  H_pylori   No  Yes
## Race_Ethnicity                                                     
## American Indian, Alaska Native, or First Nations             1    0
## Asian or Asian American                                     24    5
## Black or African-American                                   13    0
## Hispanic White                                              20    1
## Hispanic, Latino, or Latinx                                 36   11
## Mixed race/ethnicity                                        23    5
## Non-Hispanic White                                        1700  112
## Other                                                       20    1

Locations of the 41 NHWs that have H. pylori

## 
##                         California                           Colorado 
##                                 13                                  3 
##                        Connecticut                            Florida 
##                                  2                                  7 
##                            Georgia                           Illinois 
##                                  1                                  2 
##                               Iowa                          Isla Wake 
##                                  1                                  1 
##                             Kansas                           Kentucky 
##                                  2                                  1 
##                              Maine                           Maryland 
##                                  2                                  2 
##                           Michigan                          Minnesota 
##                                  1                                  2 
##                           Missouri                            Montana 
##                                  2                                  1 
##                      New Hampshire                         New Jersey 
##                                  2                                  4 
##                           New York                     North Carolina 
##                                  4                                 13 
##                       North Dakota                               Ohio 
##                                  1                                  6 
##                             Oregon Outside of the US (please specify) 
##                                  2                                  4 
##                       Pennsylvania                Prefer not to share 
##                                  2                                  9 
##                     South Carolina                              Texas 
##                                  1                                  7 
##                               Utah                           Virginia 
##                                  1                                  2 
##                         Washington                      West Virginia 
##                                  7                                  1 
##                          Wisconsin 
##                                  3

Exploring the outcome and exposures

Considering Dr. Nuno’s supervised learning with penalized logistic regression (LASSO)

## [1] 0.03831503
## 23 x 1 sparse Matrix of class "dgCMatrix"
##                      s1
## (Intercept) -0.09850932
## Q4           .         
## Q5          -1.36965693
## Q6           .         
## Q7           .         
## Q8          -1.30118070
## Q10          .         
## Q12          .         
## Q13         -0.55436438
## Q15          .         
## Q16          .         
## Q17          .         
## Q18         -0.05233716
## Q19         -0.56803125
## Q20          .         
## Q21          .         
## Q22         -1.75884004
## Q23          .         
## Q24          .         
## Q25          0.15992353
## Q26          .         
## Q27          .         
## Q28          0.15992331
## 23 x 1 Matrix of class "dgeMatrix"
##                    s1
## (Intercept) 0.9061872
## Q4          1.0000000
## Q5          0.2541942
## Q6          1.0000000
## Q7          1.0000000
## Q8          0.2722102
## Q10         1.0000000
## Q12         1.0000000
## Q13         0.5744373
## Q15         1.0000000
## Q16         1.0000000
## Q17         1.0000000
## Q18         0.9490088
## Q19         0.5666399
## Q20         1.0000000
## Q21         1.0000000
## Q22         0.1722445
## Q23         1.0000000
## Q24         1.0000000
## Q25         1.1734211
## Q26         1.0000000
## Q27         1.0000000
## Q28         1.1734209
## 0.8304813
## 
## Call:
## glm(formula = gc_outcome ~ ., family = "binomial", data = df2[, 
##     c("gc_outcome", c(selected_vars, "age", "Sex"))])
## 
## Coefficients:
##               Estimate Std. Error z value Pr(>|z|)    
## (Intercept)  -12.31939    2.23359  -5.516 3.48e-08 ***
## Q5No           3.10178    0.81589   3.802 0.000144 ***
## Q8No           2.67589    0.58247   4.594 4.35e-06 ***
## Q13No          2.17984    0.67386   3.235 0.001217 ** 
## Q18No          1.57976    0.78185   2.021 0.043327 *  
## Q19No          2.26627    0.77210   2.935 0.003333 ** 
## Q22PMS2      -18.36253 1129.64401  -0.016 0.987031    
## Q25RAD51D     16.77219 3956.18034   0.004 0.996617    
## Q28TP53       16.72468 3956.18041   0.004 0.996627    
## age            0.02977    0.01851   1.608 0.107856    
## SexMale        0.22611    0.76354   0.296 0.767132    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for binomial family taken to be 1)
## 
##     Null deviance: 201.06  on 160  degrees of freedom
## Residual deviance: 140.86  on 150  degrees of freedom
## AIC: 162.86
## 
## Number of Fisher Scoring iterations: 16
##  (Intercept)         Q5No         Q8No        Q13No        Q18No        Q19No 
## 4.464346e-06 2.223754e+01 1.452532e+01 8.844923e+00 4.853780e+00 9.643343e+00 
##      Q22PMS2    Q25RAD51D      Q28TP53          age      SexMale 
## 1.059872e-08 1.923398e+07 1.834160e+07 1.030214e+00 1.253708e+00
Characteristic OR 95% CI p-value
Q5


    ATM
    No 22.2 5.41, 154 <0.001
Q8


    BRCA1
    No 14.5 4.97, 50.3 <0.001
Q13


    CHEK2
    No 8.84 2.55, 37.4 0.001
Q18


    MSH2
    No 4.85 1.12, 26.1 0.043
Q19


    MSH6
    No 9.64 2.38, 52.8 0.003
Q22


    No
    PMS2 0.00
>0.9
Q25


    No
    RAD51D 19,233,981 0.00,
>0.9
Q28


    No
    TP53 18,341,603 0.00,
>0.9
age 1.03 0.99, 1.07 0.11
Sex


    Female
    Male 1.25 0.28, 5.83 0.8
Abbreviations: CI = Confidence Interval, OR = Odds Ratio

Unsupervised

##         y
## clusters  0  1
##        1 79 46
##        2 31  5

Cancer cases do not cleanly separate and are scattered in multiple regions. Some mild grouping but no distinct clusters. Mutation profiles do not strongly separate gastric cancer vs non-cancer patients in a linear low-dimensional structure (PCA). Clustering structure exists, but is weak and not cleanly distinct in PCA space

Principal component analysis of mutation profiles did not reveal clear separation between gastric cancer and non-cancer patients. Similarly, hierarchical clustering showed only weak group structure, suggesting that gastric cancer risk is not driven by global mutation patterns but rather by specific genetic alterations

PCA to detect global variance structure is weak/none. Clustering to see patient subgroups is weak. LASSO to detect sparse predictive features has some strong signals.

Our data suggests that there are no clear groups, but there are a few important genes. This pattern is common in biomedical data as diseases are often not cluster-driven, but are feature-driven for specific mutations.