lucy.js

// assuming you have radio inputs like this in your html:
// <input type="radio" name="gender" value="1"> Female
// <input type="radio" name="gender" value="2"> Male

// you can do something like this serverside:
function getGenderForInteger(genderInt) {
  switch (genderInt) {
    case 1: // handling the case where genderInt === 1
      return 'Female';
    case 2: // handling the case where genderInt === 2
      return 'Male';
    default: // required fallback (e.g. genderInt === 3, 4, etc? will return male)
      return 'Male';
  }
}
// and something similar to that ^ for other types of integer data you need to stringify

// and just get the string by passing the form value into above function:
app.post('/survey', function (req, res, next) {
  let gender = getGenderForInteger(req.body.gender);
  // ... the rest of your req.body values ...
});