Nutzt die oben aufgeführten Funktionen um die Metadaten des Objekts hnscc zu explorieren:

table(hnscc$alcohol)
## 
##  NO YES 
##  85 188
table(hnscc$neoplasm_site)
## 
## Alveolar Ridge Base of Tongue  Buccal Mucosa Floor of Mouth    Hard Palate 
##              7             12              8             26              5 
##    Hypopharynx         Larynx            Lip    Oral Cavity    Oral Tongue 
##              2             72              1             49             76 
##     Oropharynx         Tonsil 
##              2             19
table(hnscc$grade)
## 
##  G1  G2  G3  G4  GX 
##  23 176  71   1   8
table(hnscc$grade, useNA="always")
## 
##   G1   G2   G3   G4   GX <NA> 
##   23  176   71    1    8    0
summary(hnscc$pack_years)
##      Min.   1st Qu.    Median      Mean   3rd Qu.      Max.      NA's 
##   0.01685  30.00000  45.00000  50.62485  60.00000 300.00000       125
table(is.na(hnscc$pack_years))
## 
## FALSE  TRUE 
##   154   125
summary(hnscc$days_to_death)
##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max.    NA's 
##     0.0   218.8   443.0   789.0   999.2  6416.0       1